Apparatus for transmitting broadcast signals, apparatus for receiving broadcast signals, method for transmitting broadcast signals and method for receiving broadcast signals

ABSTRACT

The present invention provides an apparatus for transmitting broadcast signals, an apparatus for receiving broadcast signals and methods for transmitting and receiving broadcast signals. An apparatus for transmitting a broadcast signal including multimedia content using a broadcast network includes: an encoder configured to generate signaling information, wherein the signaling information indicates whether the multimedia content is to be transmitted in real time; a transmission block generator, if the signaling information indicates real-time transmission of the multimedia content, configured to divide a file contained in the multimedia content into at least one transmission block (TB) indicating a data unit that is independently encoded and transmitted; and a transmitter configured to transmit the transmission block (TB). Accordingly, the apparatus can reduce a total time needed when multimedia content is acquired and then displayed for a user.

TECHNICAL FIELD

The present invention relates to an apparatus for transmitting broadcastsignals, an apparatus for receiving broadcast signals and methods fortransmitting and receiving broadcast signals.

BACKGROUND ART

As analog broadcast signal transmission comes to an end, varioustechnologies for transmitting/receiving digital broadcast signals arebeing developed. A digital broadcast signal may include a larger amountof video/audio data than an analog broadcast signal and further includevarious types of additional data in addition to the video/audio data.

That is, a digital broadcast system can provide HD (high definition)images, multi-channel audio and various additional services. However,data transmission efficiency for transmission of large amounts of data,robustness of transmission/reception networks and network flexibility inconsideration of mobile reception equipment need to be improved fordigital broadcast.

DISCLOSURE OF INVENTION Technical Problem

An object of the present invention is to provide an apparatus and methodfor transmitting broadcast signals to multiplex data of a broadcasttransmission/reception system providing two or more different broadcastservices in a time domain and transmit the multiplexed data through thesame RF signal bandwidth and an apparatus and method for receivingbroadcast signals corresponding thereto.

Another object of the present invention is to provide an apparatus fortransmitting broadcast signals, an apparatus for receiving broadcastsignals and methods for transmitting and receiving broadcast signals toclassify data corresponding to services by components, transmit datacorresponding to each component as a data pipe, receive and process thedata

Still another object of the present invention is to provide an apparatusfor transmitting broadcast signals, an apparatus for receiving broadcastsignals and methods for transmitting and receiving broadcast signals tosignal signaling information necessary to provide broadcast signals.

The conventional art requires a considerably long time consumed forobtaining multimedia content and displaying the multimedia content for auser, so that the conventional art is inappropriate for the real-timebroadcasting environment.

Solution to Problem

To achieve the object and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, anapparatus for transmitting a broadcast signal including multimediacontent using a broadcast network includes: an encoder configured togenerate signaling information, wherein the signaling informationindicates whether the multimedia content is to be transmitted in realtime; a transmission block generator, if the signaling informationindicates real-time transmission of the multimedia content, configuredto divide a file contained in the multimedia content into at least onetransmission block (TB) indicating a data unit that is independentlyencoded and transmitted; and a transmitter configured to transmit thetransmission block (TB).

The signaling information may indicate real-time transmission of themultimedia content using at least one of a file level and a FileDelivery Table (FDT) level.

The apparatus may further include: a fragment generator configured togenerate at least one fragment indicating a data unit that isindependently encoded and reproduced through segmentation of the file.The transmission block generator may generate at least one transmissionblock (TB) indicating a data unit that is independently encoded andtransmitted through segmentation of the fragment.

The apparatus may further include: a packetizer configured to divide thetransmission block (TB) into at least one equal-sized symbol, and topacketize each symbol into at least one packet, wherein the transmittertransmits the at least one packet in generation order of thetransmission block (TB).

The transmission block generator may generate a transmission block (TB)corresponding to a fragment payload and then transmits a transmissionblock (TB) corresponding to a fragment header.

The transmission block generator may generate each of a transmissionblock (TB) corresponding to a fragment payload and a transmission block(TB) corresponding to a fragment header as a separate transmission block(TB).

A header of the packet may include fragment information havinginformation regarding file segmentation generation and segmentationconsumption; and the fragment information may include at least one of aFragment Start Indicator (SI) field indicating that the packet hasinitial data of the fragment, a Fragment Header flag (FH) fieldindicating that the packet has data of the fragment header, fragmentcompletion information indicating that generation of the transmissionblock (TB) corresponding to the fragment is completed, and a paddingbytes (PB) field indicating the number of padding bytes contained in thepacket.

The fragment completion information may include: a Fragment HeaderComplete Indicator (FC) field indicating that the packet has last dataof the fragment header; and a Fragment Header Length (FHL) fieldindicating a total number of symbols corresponding to the fragmentheader.

In accordance with another aspect of the present invention, an apparatusfor receiving broadcast signals including multimedia content using abroadcast network includes: an encoder configured to generate signalinginformation, wherein the signaling information indicates whether themultimedia content is to be transmitted in real time; a transmissionblock regenerator, if the signaling information indicates real-timetransmission of the multimedia content, configured to combine thebroadcast signals so as to reproduce at least one transmission block(TB) indicating a data unit that is independently encoded andtransmitted; and a media decoder configured to decode the transmissionblock (TB).

The signaling information may indicate real-time transmission of themultimedia content using at least one of a file level and a FileDelivery Table (FDT) level.

The apparatus may further include: a fragment regenerator, afterrecovery of a fragment header and a fragment payload is completed bycombination of the at least one transmission block (TB), configured tocombine the fragment header and the fragment payload and to reproduce afragment indicating a data unit that is independently decoded andreproduced; and the media decoder configured to decode the fragment.

The broadcast signal may include at least one packet; a header of thepacket may include fragment information having information regardingfile segmentation generation and segmentation consumption; and thefragment information may include at least one of a Fragment StartIndicator (SI) field indicating that the packet has initial data of thefragment, a Fragment Header flag (FH) field indicating that the packethas data of the fragment header, fragment completion informationindicating recovery completion of the fragment header and the fragmentpayload, and a padding bytes (PB) field indicating the number of paddingbytes contained in the packet.

The fragment regenerator, if the FH field indicates that the packet hasdata of the fragment header, may combine at least one transmission block(TB) corresponding to the fragment header so as to recover the fragmentheader. The fragment regenerator, if the FH field indicates that thepacket does not have data of the fragment header, may combine at leastone transmission block (TB) corresponding to the fragment payload so asto recover the fragment payload.

The fragment completion information may further include a FragmentHeader Complete Indicator (FC) field indicating that the packet has lastdata of the fragment header. If the FC field indicates that the packethas the last data of the fragment header, recovery of the fragmentheader and the fragment payload may be completed.

The fragment regenerator may be configured to count the number ofpackets including data of the fragment header; the fragment completioninformation may further include a Fragment Header Length (FHL) fieldindicating a total number of symbols corresponding to the fragmentheader; and if the value recorded in the FHL field is identical to thenumber of packets, recovery of the fragment header and the fragmentpayload may be completed.

Advantageous Effects of Invention

The present invention can process data according to servicecharacteristics to control QoS (Quality of Services) for each service orservice component, thereby providing various broadcast services.

The present invention can achieve transmission flexibility bytransmitting various broadcast services through the same RF signalbandwidth.

The present invention can improve data transmission efficiency andincrease robustness of transmission/reception of broadcast signals usinga MIMO system.

According to the present invention, it is possible to provide broadcastsignal transmission and reception methods and apparatus capable ofreceiving digital broadcast signals without error even with mobilereception equipment or in an indoor environment.

The apparatus for transmitting broadcast signals according to theembodiments can reduce a standby time needed for transmitting multimediacontent.

The apparatus for receiving broadcast signals according to theembodiments can reduce a standby time needed for reproducing multimediacontent.

The embodiments of the present invention can reduce a total timeconsumed for obtaining multimedia content and displaying the multimediacontent for a user.

The embodiments of the present invention can reduce an initial delaytime needed for the user who approaches a broadcast channel.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 illustrates a structure of an apparatus for transmittingbroadcast signals for future broadcast services according to anembodiment of the present invention.

FIG. 2 illustrates an input formatting block according to one embodimentof the present invention.

FIG. 3 illustrates an input formatting block according to anotherembodiment of the present invention.

FIG. 4 illustrates an input formatting block according to anotherembodiment of the present invention.

FIG. 5 illustrates a BICM block according to an embodiment of thepresent invention.

FIG. 6 illustrates a BICM block according to another embodiment of thepresent invention.

FIG. 7 illustrates a frame building block according to one embodiment ofthe present invention.

FIG. 8 illustrates an OFMD generation block according to an embodimentof the present invention.

FIG. 9 illustrates a structure of an apparatus for receiving broadcastsignals for future broadcast services according to an embodiment of thepresent invention.

FIG. 10 illustrates a frame structure according to an embodiment of thepresent invention.

FIG. 11 illustrates a signaling hierarchy structure of the frameaccording to an embodiment of the present invention.

FIG. 12 illustrates preamble signaling data according to an embodimentof the present invention.

FIG. 13 illustrates PLS1 data according to an embodiment of the presentinvention.

FIG. 14 illustrates PLS2 data according to an embodiment of the presentinvention.

FIG. 15 illustrates PLS2 data according to another embodiment of thepresent invention.

FIG. 16 illustrates a logical structure of a frame according to anembodiment of the present invention.

FIG. 17 illustrates PLS mapping according to an embodiment of thepresent invention.

FIG. 18 illustrates EAC mapping according to an embodiment of thepresent invention.

FIG. 19 illustrates FIC mapping according to an embodiment of thepresent invention.

FIG. 20 illustrates a type of DP according to an embodiment of thepresent invention.

FIG. 21 illustrates DP mapping according to an embodiment of the presentinvention.

FIG. 22 illustrates an FEC structure according to an embodiment of thepresent invention.

FIG. 23 illustrates a bit interleaving according to an embodiment of thepresent invention.

FIG. 24 illustrates a cell-word demultiplexing according to anembodiment of the present invention.

FIG. 25 illustrates a time interleaving according to an embodiment ofthe present invention.

FIG. 26 illustrates the basic operation of a twisted row-column blockinterleaver according to an embodiment of the present invention.

FIG. 27 illustrates an operation of a twisted row-column blockinterleaver according to another embodiment of the present invention.

FIG. 28 illustrates a diagonal-wise reading pattern of a twistedrow-column block interleaver according to an embodiment of the presentinvention.

FIG. 29 illustrates interlaved XFECBLOCKs from each interleaving arrayaccording to an embodiment of the present invention.

FIG. 30 illustrates a data processing time when a File Delivery overUnidirectional Transport (FLUTE) protocol is used.

FIG. 31 illustrates a Real-Time Object Delivery over UnidirectionalTransport (ROUTE) protocol stack according to an embodiment of thepresent invention.

FIG. 32 illustrates a data structure of file-based multimedia contentaccording to an embodiment of the present invention.

FIG. 33 illustrates a media segment structure of MPEG-DASH to which thedata structure is applied.

FIG. 34 illustrates a data processing time using a ROUTE protocolaccording to an embodiment of the present invention.

FIG. 35 illustrates a Layered Coding Transport (LCT) packet structurefor file transmission according to an embodiment of the presentinvention.

FIG. 36 illustrates a structure of an LCT packet according to anotherembodiment of the present invention.

FIG. 37 illustrates real-time broadcast support information signalingbased on FDT according to an embodiment of the present invention.

FIG. 38 is a block diagram illustrating a broadcast signal transmissionapparatus according to an embodiment of the present invention.

FIG. 39 is a block diagram illustrating a broadcast signal transmissionapparatus according to an embodiment of the present invention.

FIG. 40 is a flowchart illustrating a process for generating andtransmitting in real time the file-based multimedia content according toan embodiment of the present invention.

FIG. 41 is a flowchart illustrating a process for allowing the broadcastsignal transmission apparatus to generate packets using a packetizeraccording to an embodiment of the present invention.

FIG. 42 is a flowchart illustrating a process forgenerating/transmitting in real time the file-based multimedia contentaccording to another embodiment of the present invention.

FIG. 43 is a block diagram illustrating a file-based multimedia contentreceiver according to an embodiment of the present invention.

FIG. 44 is a block diagram illustrating a file-based multimedia contentreceiver according to an embodiment of the present invention.

FIG. 45 is a flowchart illustrating a process for receiving/consuming afile-based multimedia content according to an embodiment of the presentinvention.

FIG. 46 is a flowchart illustrating a process for receiving/consuming inreal time a file-based multimedia content according to anotherembodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. The detailed description, which will be given below withreference to the accompanying drawings, is intended to explain exemplaryembodiments of the present invention, rather than to show the onlyembodiments that can be implemented according to the present invention.The following detailed description includes specific details in order toprovide a thorough understanding of the present invention. However, itwill be apparent to those skilled in the art that the present inventionmay be practiced without such specific details.

Although most terms used in the present invention have been selectedfrom general ones widely used in the art, some terms have beenarbitrarily selected by the applicant and their meanings are explainedin detail in the following description as needed. Thus, the presentinvention should be understood based upon the intended meanings of theterms rather than their simple names or meanings.

The present invention provides apparatuses and methods for transmittingand receiving broadcast signals for future broadcast services. Futurebroadcast services according to an embodiment of the present inventioninclude a terrestrial broadcast service, a mobile broadcast service, aUHDTV service, etc.

The apparatuses and methods for transmitting according to an embodimentof the present invention may be categorized into a base profile for theterrestrial broadcast service, a handheld profile for the mobilebroadcast service and an advanced profile for the UHDTV service. In thiscase, the base profile can be used as a profile for both the terrestrialbroadcast service and the mobile broadcast service. That is, the baseprofile can be used to define a concept of a profile which includes themobile profile. This can be changed according to intention of thedesigner.

The present invention may process broadcast signals for the futurebroadcast services through non-MIMO (Multiple Input Multiple Output) orMIMO according to one embodiment. A non-MIMO scheme according to anembodiment of the present invention may include a MISO (Multiple InputSingle Output) scheme, a SISO (Single Input Single Output) scheme, etc.

While MISO or MIMO uses two antennas in the following for convenience ofdescription, the present invention is applicable to systems using two ormore antennas.

The present invention may defines three physical layer (PL) profiles(base, handheld and advanced profiles) each optimized to minimizereceiver complexity while attaining the performance required for aparticular use case. The physical layer (PHY) profiles are subsets ofall configurations that a corresponding receiver should implement.

The three PHY profiles share most of the functional blocks but differslightly in specific blocks and/or parameters. Additional PHY profilescan be defined in the future. For the system evolution, future profilescan also be multiplexed with the existing profiles in a single RFchannel through a future extension frame (FEF). The details of each PHYprofile are described below.

1. Base Profile

The base profile represents a main use case for fixed receiving devicesthat are usually connected to a roof-top antenna. The base profile alsoincludes portable devices that could be transported to a place butbelong to a relatively stationary reception category. Use of the baseprofile could be extended to handheld devices or even vehicular by someimproved implementations, but those use cases are not expected for thebase profile receiver operation.

Target SNR range of reception is from approximately 10 to 20 dB, whichincludes the 15 dB SNR reception capability of the existing broadcastsystem (e.g. ATSC A/53). The receiver complexity and power consumptionis not as critical as in the batteryoperated handheld devices, whichwill use the handheld profile. Key system parameters for the baseprofile are listed in below table 1.

TABLE 1 LDPC codeword length 16K, 64K bits Constellation size 4~10 bpcu(bits per channel use) Time de-interleaving memory size ≦2¹⁹ data cellsPilot patterns Pilot pattern for fixed reception FFT size 16K, 32Kpoints

2. Handheld Profile

The handheld profile is designed for use in handheld and vehiculardevices that operate with battery power. The devices can be moving withpedestrian or vehicle speed. The power consumption as well as thereceiver complexity is very important for the implementation of thedevices of the handheld profile. The target SNR range of the handheldprofile is approximately 0 to 10 dB, but can be configured to reachbelow 0 dB when intended for deeper indoor reception.

In addition to low SNR capability, resilience to the Doppler Effectcaused by receiver mobility is the most important performance attributeof the handheld profile. Key system parameters for the handheld profileare listed in the below table 2.

TABLE 2 LDPC codeword length 16K bits Constellation size 2~8 bpcu Timede-interleaving memory size ≦2¹⁸ data cells Pilot patterns Pilotpatterns for mobile and indoor reception FFT size 8K, 16K points

3. Advanced Profile

The advanced profile provides highest channel capacity at the cost ofmore implementation complexity. This profile requires using MIMOtransmission and reception, and UHDTV service is a target use case forwhich this profile is specifically designed. The increased capacity canalso be used to allow an increased number of services in a givenbandwidth, e.g., multiple SDTV or HDTV services.

The target SNR range of the advanced profile is approximately 20 to 30dB. MIMO transmission may initially use existing elliptically-polarizedtransmission equipment, with extension to full-power cross-polarizedtransmission in the future. Key system parameters for the advancedprofile are listed in below table 3.

TABLE 3 LDPC codeword length 16K, 64K bits Constellation size 8~12 bpcuTime de-interleaving memory size ≦2¹⁹ data cells Pilot patterns Pilotpattern for fixed reception FFT size 16K, 32K points

In this case, the base profile can be used as a profile for both theterrestrial broadcast service and the mobile broadcast service. That is,the base profile can be used to define a concept of a profile whichincludes the mobile profile. Also, the advanced profile can be dividedadvanced profile for a base profile with MIMO and advanced profile for ahandheld profile with MIMO. Moreover, the three profiles can be changedaccording to intention of the designer.

The following terms and definitions may apply to the present invention.The following terms and definitions can be changed according to design.

auxiliary stream: sequence of cells carrying data of as yet undefinedmodulation and coding, which may be used for future extensions or asrequired by broadcasters or network operators

base data pipe: data pipe that carries service signaling data

baseband frame (or BBFRAME): set of Kbch bits which form the input toone FEC encoding process (BCH and LDPC encoding)

cell: modulation value that is carried by one carrier of the OFDMtransmission

coded block: LDPC-encoded block of PLS1 data or one of the LDPC-encodedblocks of PLS2 data

data pipe: logical channel in the physical layer that carries servicedata or related metadata, which may carry one or multiple service(s) orservice component(s).

data pipe unit: a basic unit for allocating data cells to a DP in aframe.

data symbol: OFDM symbol in a frame which is not a preamble symbol (theframe signaling symbol and frame edge symbol is included in the datasymbol)

DP_ID: this 8 bit field identifies uniquely a DP within the systemidentified by the SYSTEM_ID

dummy cell: cell carrying a pseudorandom value used to fill theremaining capacity not used for PLS signaling, DPs or auxiliary streams

emergency alert channel: part of a frame that carries EAS informationdata

frame: physical layer time slot that starts with a preamble and endswith a frame edge symbol

frame repetition unit: a set of frames belonging to same or differentphysical layer profile including a FEF, which is repeated eight times ina super-frame

fast information channel: a logical channel in a frame that carries themapping information between a service and the corresponding base DP

FECBLOCK: set of LDPC-encoded bits of a DP data

FFT size: nominal FFT size used for a particular mode, equal to theactive symbol period Ts expressed in cycles of the elementary period T

frame signaling symbol: OFDM symbol with higher pilot density used atthe start of a frame in certain combinations of FFT size, guard intervaland scattered pilot pattern, which carries a part of the PLS data

frame edge symbol: OFDM symbol with higher pilot density used at the endof a frame in certain combinations of FFT size, guard interval andscattered pilot pattern

frame-group: the set of all the frames having the same PHY profile typein a super-frame.

future extension frame: physical layer time slot within the super-framethat could be used for future extension, which starts with a preamble

Futurecast UTB system: proposed physical layer broadcasting system, ofwhich the input is one or more MPEG2-TS or IP or general stream(s) andof which the output is an RF signal

input stream: A stream of data for an ensemble of services delivered tothe end users by the system.

normal data symbol: data symbol excluding the frame signaling symbol andthe frame edge symbol

PHY profile: subset of all configurations that a corresponding receivershould implement

PLS: physical layer signaling data consisting of PLS1 and PLS2

PLS1: a first set of PLS data carried in the FSS symbols having a fixedsize, coding and modulation, which carries basic information about thesystem as well as the parameters needed to decode the PLS2

NOTE: PLS1 data remains constant for the duration of a frame-group.

PLS2: a second set of PLS data transmitted in the FSS symbol, whichcarries more detailed PLS data about the system and the DPs

PLS2 dynamic data: PLS2 data that may dynamically change frame-by-frame

PLS2 static data: PLS2 data that remains static for the duration of aframe-group

preamble signaling data: signaling data carried by the preamble symboland used to identify the basic mode of the system

preamble symbol: fixed-length pilot symbol that carries basic PLS dataand is located in the beginning of a frame

NOTE: The preamble symbol is mainly used for fast initial band scan todetect the system signal, its timing, frequency offset, and FFTsize.

reserved for future use: not defined by the present document but may bedefined in future

superframe: set of eight frame repetition units

time interleaving block (TI block): set of cells within which timeinterleaving is carried out, corresponding to one use of the timeinterleaver memory

TI group: unit over which dynamic capacity allocation for a particularDP is carried out, made up of an integer, dynamically varying number ofXFECBLOCKs.

NOTE: The TI group may be mapped directly to one frame or may be mappedto multiple frames. It may contain one or more TI blocks.

Type 1 DP: DP of a frame where all DPs are mapped into the frame in TDMfashion

Type 2 DP: DP of a frame where all DPs are mapped into the frame in FDMfashion

XFECBLOCK: set of Ncells cells carrying all the bits of one LDPCFECBLOCK

FIG. 1 illustrates a structure of an apparatus for transmittingbroadcast signals for future broadcast services according to anembodiment of the present invention.

The apparatus for transmitting broadcast signals for future broadcastservices according to an embodiment of the present invention can includean input formatting block 1000, a BICM (Bit interleaved coding &modulation) block 1010, a frame structure block 1020, an OFDM(Orthogonal Frequency Division Multiplexing) generation block 1030 and asignaling generation block 1040. A description will be given of theoperation of each module of the apparatus for transmitting broadcastsignals.

IP stream/packets and MPEG2-TS are the main input formats, other streamtypes are handled as General Streams. In addition to these data inputs,Management Information is input to control the scheduling and allocationof the corresponding bandwidth for each input stream. One or multiple TSstream(s), IP stream(s) and/or General Stream(s) inputs aresimultaneously allowed.

The input formatting block 1000 can demultiplex each input stream intoone or multiple data pipe(s), to each of which an independent coding andmodulation is applied. The data pipe (DP) is the basic unit forrobustness control, thereby affecting quality-of-service (QoS). One ormultiple service(s) or service component(s) can be carried by a singleDP. Details of operations of the input formatting block 1000 will bedescribed later.

The data pipe is a logical channel in the physical layer that carriesservice data or related metadata, which may carry one or multipleservice(s) or service component(s).

Also, the data pipe unit: a basic unit for allocating data cells to a DPin a frame.

In the BICM block 1010, parity data is added for error correction andthe encoded bit streams are mapped to complex-value constellationsymbols. The symbols are interleaved across a specific interleavingdepth that is used for the corresponding DP. For the advanced profile,MIMO encoding is performed in the BICM block 1010 and the additionaldata path is added at the output for MIMO transmission. Details ofoperations of the BICM block 1010 will be described later.

The Frame Building block 1020 can map the data cells of the input DPsinto the OFDM symbols within a frame. After mapping, the frequencyinterleaving is used for frequency-domain diversity, especially tocombat frequency-selective fading channels. Details of operations of theFrame Building block 1020 will be described later.

After inserting a preamble at the beginning of each frame, the OFDMGeneration block 1030 can apply conventional OFDM modulation having acyclic prefix as guard interval. For antenna space diversity, adistributed MISO scheme is applied across the transmitters. In addition,a Peak-to-Average Power Reduction (PAPR) scheme is performed in the timedomain. For flexible network planning, this proposal provides a set ofvarious FFT sizes, guard interval lengths and corresponding pilotpatterns. Details of operations of the OFDM Generation block 1030 willbe described later.

The Signaling Generation block 1040 can create physical layer signalinginformation used for the operation of each functional block. Thissignaling information is also transmitted so that the services ofinterest are properly recovered at the receiver side. Details ofoperations of the Signaling Generation block 1040 will be describedlater.

FIGS. 2, 3 and 4 illustrate the input formatting block 1000 according toembodiments of the present invention. A description will be given ofeach figure.

FIG. 2 illustrates an input formatting block according to one embodimentof the present invention. FIG. 2 shows an input formatting module whenthe input signal is a single input stream.

The input formatting block illustrated in FIG. 2 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

The input to the physical layer may be composed of one or multiple datastreams. Each data stream is carried by one DP. The mode adaptationmodules slice the incoming data stream into data fields of the basebandframe (BBF). The system supports three types of input data streams:MPEG2-TS, Internet protocol (IP) and Generic stream (GS). MPEG2-TS ischaracterized by fixed length (188 byte) packets with the first bytebeing a sync-byte (0x47). An IP stream is composed of variable length IPdatagram packets, as signaled within IP packet headers. The systemsupports both IPv4 and IPv6 for the IP stream. GS may be composed ofvariable length packets or constant length packets, signaled withinencapsulation packet headers.

(a) shows a mode adaptation block 2000 and a stream adaptation 2010 forsignal DP and (b) shows a PLS generation block 2020 and a PLS scrambler2030 for generating and processing PLS data. A description will be givenof the operation of each block.

The Input Stream Splitter splits the input TS, IP, GS streams intomultiple service or service component (audio, video, etc.) streams. Themode adaptation module 2010 is comprised of a CRC Encoder, BB (baseband)Frame Slicer, and BB Frame Header Insertion block.

The CRC Encoder provides three kinds of CRC encoding for error detectionat the user packet (UP) level, i.e., CRC-8, CRC-16, and CRC-32. Thecomputed CRC bytes are appended after the UP. CRC-8 is used for TSstream and CRC-32 for IP stream. If the GS stream doesn't provide theCRC encoding, the proposed CRC encoding should be applied.

BB Frame Slicer maps the input into an internal logical-bit format. Thefirst received bit is defined to be the MSB. The BB Frame Slicerallocates a number of input bits equal to the available data fieldcapacity. To allocate a number of input bits equal to the BBF payload,the UP packet stream is sliced to fit the data field of BBF.

BB Frame Header Insertion block can insert fixed length BBF header of 2bytes is inserted in front of the BB Frame. The BBF header is composedof STUFFI (1 bit), SYNCD (13 bits), and RFU (2 bits). In addition to thefixed 2-Byte BBF header, BBF can have an extension field (1 or 3 bytes)at the end of the 2-byte BBF header.

The stream adaptation 2010 is comprised of stuffing insertion block andBB scrambler.

The stuffing insertion block can insert stuffing field into a payload ofa BB frame. If the input data to the stream adaptation is sufficient tofill a BB-Frame, STUFFI is set to ‘0’ and the BBF has no stuffing field.Otherwise STUFFI is set to ‘1’ and the stuffing field is insertedimmediately after the BBF header. The stuffing field comprises two bytesof the stuffing field header and a variable size of stuffing data.

The BB scrambler scrambles complete BBF for energy dispersal. Thescrambling sequence is synchronous with the BBF. The scrambling sequenceis generated by the feed-back shift register.

The PLS generation block 2020 can generate physical layer signaling(PLS) data. The PLS provides the receiver with a means to accessphysical layer DPs. The PLS data consists of PLS1 data and PLS2 data.

The PLS1 data is a first set of PLS data carried in the FSS symbols inthe frame having a fixed size, coding and modulation, which carriesbasic information about the system as well as the parameters needed todecode the PLS2 data. The PLS1 data provides basic transmissionparameters including parameters required to enable the reception anddecoding of the PLS2 data. Also, the PLS1 data remains constant for theduration of a frame-group.

The PLS2 data is a second set of PLS data transmitted in the FSS symbol,which carries more detailed PLS data about the system and the DPs. ThePLS2 contains parameters that provide sufficient information for thereceiver to decode the desired DP. The PLS2 signaling further consistsof two types of parameters, PLS2 Static data (PLS2-STAT data) and PLS2dynamic data (PLS2-DYN data). The PLS2 Static data is PLS2 data thatremains static for the duration of a frame-group and the PLS2 dynamicdata is PLS2 data that may dynamically change frame-by-frame.

Details of the PLS data will be described later.

The PLS scrambler 2030 can scramble the generated PLS data for energydispersal.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 3 illustrates an input formatting block according to anotherembodiment of the present invention.

The input formatting block illustrated in FIG. 3 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

FIG. 3 shows a mode adaptation block of the input formatting block whenthe input signal corresponds to multiple input streams.

The mode adaptation block of the input formatting block for processingthe multiple input streams can independently process the multiple inputstreams.

Referring to FIG. 3, the mode adaptation block for respectivelyprocessing the multiple input streams can include an input streamsplitter 3000, an input stream synchronizer 3010, a compensating delayblock 3020, a null packet deletion block 3030, a head compression block3040, a CRC encoder 3050, a BB frame slicer 3060 and a BB headerinsertion block 3070. Description will be given of each block of themode adaptation block.

Operations of the CRC encoder 3050, BB frame slicer 3060 and BB headerinsertion block 3070 correspond to those of the CRC encoder, BB frameslicer and BB header insertion block described with reference to FIG. 2and thus description thereof is omitted.

The input stream splitter 3000 can split the input TS, IP, GS streamsinto multiple service or service component (audio, video, etc.) streams.

The input stream synchronizer 3010 may be referred as ISSY. The ISSY canprovide suitable means to guarantee Constant Bit Rate (CBR) and constantend-to-end transmission delay for any input data format. The ISSY isalways used for the case of multiple DPs carrying TS, and optionallyused for multiple DPs carrying GS streams.

The compensating delay block 3020 can delay the split TS packet streamfollowing the insertion of ISSY information to allow a TS packetrecombining mechanism without requiring additional memory in thereceiver.

The null packet deletion block 3030, is used only for the TS inputstream case. Some TS input streams or split TS streams may have a largenumber of null-packets present in order to accommodate VBR (variablebit-rate) services in a CBR TS stream. In this case, in order to avoidunnecessary transmission overhead, null-packets can be identified andnot transmitted. In the receiver, removed null-packets can bere-inserted in the exact place where they were originally by referenceto a deleted null-packet (DNP) counter that is inserted in thetransmission, thus guaranteeing constant bit-rate and avoiding the needfor time-stamp (PCR) updating.

The head compression block 3040 can provide packet header compression toincrease transmission efficiency for TS or IP input streams. Because thereceiver can have a priori information on certain parts of the header,this known information can be deleted in the transmitter.

For Transport Stream, the receiver has a-priori information about thesync-byte configuration (0x47) and the packet length (188 Byte). If theinput TS stream carries content that has only one PID, i.e., for onlyone service component (video, audio, etc.) or service sub-component (SVCbase layer, SVC enhancement layer, MVC base view or MVC dependentviews), TS packet header compression can be applied (optionally) to theTransport Stream. IP packet header compression is used optionally if theinput steam is an IP stream.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 4 illustrates an input formatting block according to anotherembodiment of the present invention.

The input formatting block illustrated in FIG. 4 corresponds to anembodiment of the input formatting block 1000 described with referenceto FIG. 1.

FIG. 4 illustrates a stream adaptation block of the input formattingmodule when the input signal corresponds to multiple input streams.

Referring to FIG. 4, the mode adaptation block for respectivelyprocessing the multiple input streams can include a scheduler 4000, an1-Frame delay block 4010, a stuffing insertion block 4020, an in-bandsignaling 4030, a BB Frame scrambler 4040, a PLS generation block 4050and a PLS scrambler 4060. Description will be given of each block of thestream adaptation block.

Operations of the stuffing insertion block 4020, the BB Frame scrambler4040, the PLS generation block 4050 and the PLS scrambler 4060correspond to those of the stuffing insertion block, BB scrambler, PLSgeneration block and the PLS scrambler described with reference to FIG.2 and thus description thereof is omitted.

The scheduler 4000 can determine the overall cell allocation across theentire frame from the amount of FECBLOCKs of each DP. Including theallocation for PLS, EAC and FIC, the scheduler generate the values ofPLS2-DYN data, which is transmitted as in-band signaling or PLS cell inFSS of the frame. Details of FECBLOCK, EAC and FIC will be describedlater.

The 1-Frame delay block 4010 can delay the input data by onetransmission frame such that scheduling information about the next framecan be transmitted through the current frame for in-band signalinginformation to be inserted into the DPs.

The in-band signaling 4030 can insert un-delayed part of the PLS2 datainto a DP of a frame.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 5 illustrates a BICM block according to an embodiment of thepresent invention.

The BICM block illustrated in FIG. 5 corresponds to an embodiment of theBICM block 1010 described with reference to FIG. 1.

As described above, the apparatus for transmitting broadcast signals forfuture broadcast services according to an embodiment of the presentinvention can provide a terrestrial broadcast service, mobile broadcastservice, UHDTV service, etc.

Since QoS (quality of service) depends on characteristics of a serviceprovided by the apparatus for transmitting broadcast signals for futurebroadcast services according to an embodiment of the present invention,data corresponding to respective services needs to be processed throughdifferent schemes. Accordingly, the a BICM block according to anembodiment of the present invention can independently process DPs inputthereto by independently applying SISO, MISO and MIMO schemes to thedata pipes respectively corresponding to data paths. Consequently, theapparatus for transmitting broadcast signals for future broadcastservices according to an embodiment of the present invention can controlQoS for each service or service component transmitted through each DP.

(a) shows the BICM block shared by the base profile and the handheldprofile and (b) shows the BICM block of the advanced profile.

The BICM block shared by the base profile and the handheld profile andthe BICM block of the advanced profile can include plural processingblocks for processing each DP.

A description will be given of each processing block of the BICM blockfor the base profile and the handheld profile and the BICM block for theadvanced profile.

A processing block 5000 of the BICM block for the base profile and thehandheld profile can include a Data FEC encoder 5010, a bit interleaver5020, a constellation mapper 5030, an SSD (Signal Space Diversity)encoding block 5040 and a time interleaver 5050.

The Data FEC encoder 5010 can perform the FEC encoding on the input BBFto generate FECBLOCK procedure using outer coding (BCH), and innercoding (LDPC). The outer coding (BCH) is optional coding method. Detailsof operations of the Data FEC encoder 5010 will be described later.

The bit interleaver 5020 can interleave outputs of the Data FEC encoder5010 to achieve optimized performance with combination of the LDPC codesand modulation scheme while providing an efficiently implementablestructure. Details of operations of the bit interleaver 5020 will bedescribed later.

The constellation mapper 5030 can modulate each cell word from the bitinterleaver 5020 in the base and the handheld profiles, or cell wordfrom the Cell-word demultiplexer 5010-1 in the advanced profile usingeither QPSK, QAM-16, non-uniform QAM (NUQ-64, NUQ-256, NUQ-1024) ornon-uniform constellation (NUC-16, NUC64, NUC-256, NUC-1024) to give apower-normalized constellation point, e₁. This constellation mapping isapplied only for DPs. Observe that QAM-16 and NUQs are square shaped,while NUCs have arbitrary shape. When each constellation is rotated byany multiple of 90 degrees, the rotated constellation exactly overlapswith its original one. This “rotation-sense” symmetric property makesthe capacities and the average powers of the real and imaginarycomponents equal to each other. Both NUQs and NUCs are definedspecifically for each code rate and the particular one used is signaledby the parameter DP_MOD filed in PLS2 data.

The SSD encoding block 5040 can precode cells in two (2D), three (3D),and four (4D) dimensions to increase the reception robustness underdifficult fading conditions.

The time interleaver 5050 can operates at the DP level. The parametersof time interleaving (TI) may be set differently for each DP. Details ofoperations of the time interleaver 5050 will be described later.

A processing block 5000-1 of the BICM block for the advanced profile caninclude the Data FEC encoder, bit interleaver, constellation mapper, andtime interleaver. However, the processing block 5000-1 is distinguishedfrom the processing block 5000 further includes a cell-worddemultiplexer 5010-1 and a MIMO encoding block 5020-1.

Also, the operations of the Data FEC encoder, bit interleaver,constellation mapper, and time interleaver in the processing block5000-1 correspond to those of the Data FEC encoder 5010, bit interleaver5020, constellation mapper 5030, and time interleaver 5050 described andthus description thereof is omitted.

The cell-word demultiplexer 5010-1 is used for the DP of the advancedprofile to divide the single cell-word stream into dual cell-wordstreams for MIMO processing. Details of operations of the cell-worddemultiplexer 5010-1 will be described later.

The MIMO encoding block 5020-1 can processing the output of thecell-word demultiplexer 5010-1 using MIMO encoding scheme. The MIMOencoding scheme was optimized for broadcasting signal transmission. TheMIMO technology is a promising way to get a capacity increase but itdepends on channel characteristics. Especially for broadcasting, thestrong LOS component of the channel or a difference in the receivedsignal power between two antennas caused by different signal propagationcharacteristics makes it difficult to get capacity gain from MIMO. Theproposed MIMO encoding scheme overcomes this problem using arotation-based pre-coding and phase randomization of one of the MIMOoutput signals.

MIMO encoding is intended for a 2×2 MIMO system requiring at least twoantennas at both the transmitter and the receiver. Two MIMO encodingmodes are defined in this proposal; full-rate spatial multiplexing(FR-SM) and full-rate full-diversity spatial multiplexing (FRFD-SM). TheFR-SM encoding provides capacity increase with relatively smallcomplexity increase at the receiver side while the FRFD-SM encodingprovides capacity increase and additional diversity gain with a greatcomplexity increase at the receiver side. The proposed MIMO encodingscheme has no restriction on the antenna polarity configuration.

MIMO processing is required for the advanced profile frame, which meansall DPs in the advanced profile frame are processed by the MIMO encoder.MIMO processing is applied at DP level. Pairs of the ConstellationMapper outputs NUQ (e_(1,i) and e_(2,i)) are fed to the input of theMIMO Encoder. Paired MIMO Encoder output (g1,i and g2,i) is transmittedby the same carrier k and OFDM symbol 1 of their respective TX antennas.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 6 illustrates a BICM block according to another embodiment of thepresent invention.

The BICM block illustrated in FIG. 6 corresponds to an embodiment of theBICM block 1010 described with reference to FIG. 1.

FIG. 6 illustrates a BICM block for protection of physical layersignaling (PLS), emergency alert channel (EAC) and fast informationchannel (FIC). EAC is a part of a frame that carries EAS informationdata and FIC is a logical channel in a frame that carries the mappinginformation between a service and the corresponding base DP. Details ofthe EAC and FIC will be described later.

Referring to FIG. 6, the BICM block for protection of PLS, EAC and FICcan include a PLS FEC encoder 6000, a bit interleaver 6010, aconstellation mapper 6020 and time interleaver 6030.

Also, the PLS FEC encoder 6000 can include a scrambler, BCHencoding/zero insertion block, LDPC encoding block and LDPC paritypunturing block. Description will be given of each block of the BICMblock.

The PLS FEC encoder 6000 can encode the scrambled PLS1/2 data, EAC andFIC section.

The scrambler can scramble PLS1 data and PLS2 data before BCH encodingand shortened and punctured LDPC encoding.

The BCH encoding/zero insertion block can perform outer encoding on thescrambled PLS1/2 data using the shortened BCH code for PLS protectionand insert zero bits after the BCH encoding. For PLS1 data only, theoutput bits of the zero insertion may be permutted before LDPC encoding.

The LDPC encoding block can encode the output of the BCH encoding/zeroinsertion block using LDPC code. To generate a complete coded block,C_(ldpc), parity bits, P_(ldpc) are encoded systematically from eachzero-inserted PLS information block, I_(ldpc) and appended after it.

Math Figure 1

C _(ldpc) =[I _(ldpc) P _(ldpc) ]=[i ₀ ,i ₁ , . . . ,i _(K) _(ldpc) ⁻¹,p ₀ ,p ₁ , . . . ,p _(N) _(ldpc) _(−K) _(ldpc) ⁻¹]  [Math. 1]

The LDPC code parameters for PLS1 and PLS2 are as following table 4.

TABLE 4 Signaling Type K_(sig) K_(bch) N_(bch) _(—) _(parity) K_(ldpc)(=N_(bch)) N_(ldpc) N_(ldpc) _(—) _(parity) code rate Q_(ldpc) PLS1 3421020 60 1080 4320 3240 1/4 36 PLS2 <1021 >1020 2100 2160 7200 5040 3/1056

The LDPC parity punturing block can perform puncturing on the PLS1 dataand PLS 2 data.

When shortening is applied to the PLS1 data protection, some LDPC paritybits are punctured after LDPC encoding. Also, for the PLS2 dataprotection, the LDPC parity bits of PLS2 are punctured after LDPCencoding. These punctured bits are not transmitted.

The bit interleaver 6010 can interleave the each shortened and puncturedPLS1 data and PLS2 data.

The constellation mapper 6020 can map the bit ineterlaeved PLS1 data andPLS2 data onto constellations.

The time interleaver 6030 can interleave the mapped PLS1 data and PLS2data.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 7 illustrates a frame building block according to one embodiment ofthe present invention.

The frame building block illustrated in FIG. 7 corresponds to anembodiment of the frame building block 1020 described with reference toFIG. 1.

Referring to FIG. 7, the frame building block can include a delaycompensation block 7000, a cell mapper 7010 and a frequency interleaver7020. Description will be given of each block of the frame buildingblock.

The delay compensation block 7000 can adjust the timing between the datapipes and the corresponding PLS data to ensure that they are co-timed atthe transmitter end. The PLS data is delayed by the same amount as datapipes are by addressing the delays of data pipes caused by the InputFormatting block and BICM block. The delay of the BICM block is mainlydue to the time interleaver. In-band signaling data carries informationof the next TI group so that they are carried one frame ahead of the DPsto be signaled. The Delay Compensating block delays in-band signalingdata accordingly.

The cell mapper 7010 can map PLS, EAC, FIC, DPs, auxiliary streams anddummy cells into the active carriers of the OFDM symbols in the frame.The basic function of the cell mapper 7010 is to map data cells producedby the TIs for each of the DPs, PLS cells, and EAC/FIC cells, if any,into arrays of active OFDM cells corresponding to each of the OFDMsymbols within a frame. Service signaling data (such as PSI (programspecific information)/SI) can be separately gathered and sent by a datapipe. The Cell Mapper operates according to the dynamic informationproduced by the scheduler and the configuration of the frame structure.Details of the frame will be described later.

The frequency interleaver 7020 can randomly interleave data cellsreceived from the cell mapper 7010 to provide frequency diversity. Also,the frequency interleaver 7020 can operate on very OFDM symbol paircomprised of two sequential OFDM symbols using a differentinterleaving-seed order to get maximum interleaving gain in a singleframe. Details of operations of the frequency interleaver 7020 will bedescribed later.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions.

FIG. 8 illustrates an OFMD generation block according to an embodimentof the present invention.

The OFMD generation block illustrated in FIG. 8 corresponds to anembodiment of the OFMD generation block 1030 described with reference toFIG. 1.

The OFDM generation block modulates the OFDM carriers by the cellsproduced by the Frame Building block, inserts the pilots, and producesthe time domain signal for transmission. Also, this block subsequentlyinserts guard intervals, and applies PAPR (Peak-to-Average Power Radio)reduction processing to produce the final RF signal.

Referring to FIG. 8, the frame building block can include a pilot andreserved tone insertion block 8000, a 2D-eSFN encoding block 8010, anIFFT (Inverse Fast Fourier Transform) block 8020, a PAPR reduction block8030, a guard interval insertion block 8040, a preamble insertion block8050, other system insertion block 8060 and a DAC block 8070.Description will be given of each block of the frame building block.

The pilot and reserved tone insertion block 8000 can insert pilots andthe reserved tone.

Various cells within the OFDM symbol are modulated with referenceinformation, known as pilots, which have transmitted values known apriori in the receiver. The information of pilot cells is made up ofscattered pilots, continual pilots, edge pilots, FSS (frame signalingsymbol) pilots and FES (frame edge symbol) pilots. Each pilot istransmitted at a particular boosted power level according to pilot typeand pilot pattern. The value of the pilot information is derived from areference sequence, which is a series of values, one for eachtransmitted carrier on any given symbol. The pilots can be used forframe synchronization, frequency synchronization, time synchronization,channel estimation, and transmission mode identification, and also canbe used to follow the phase noise.

Reference information, taken from the reference sequence, is transmittedin scattered pilot cells in every symbol except the preamble, FSS andFES of the frame. Continual pilots are inserted in every symbol of theframe. The number and location of continual pilots depends on both theFFT size and the scattered pilot pattern. The edge carriers are edgepilots in every symbol except for the preamble symbol. They are insertedin order to allow frequency interpolation up to the edge of thespectrum. FSS pilots are inserted in FSS(s) and FES pilots are insertedin FES. They are inserted in order to allow time interpolation up to theedge of the frame.

The system according to an embodiment of the present invention supportsthe SFN network, where distributed MISO scheme is optionally used tosupport very robust transmission mode. The 2D-eSFN is a distributed MISOscheme that uses multiple TX antennas, each of which is located in thedifferent transmitter site in the SFN network.

The 2D-eSFN encoding block 8010 can process a 2D-eSFN processing todistorts the phase of the signals transmitted from multipletransmitters, in order to create both time and frequency diversity inthe SFN configuration. Hence, burst errors due to low flat fading ordeep-fading for a long time can be mitigated.

The IFFT block 8020 can modulate the output from the 2D-eSFN encodingblock 8010 using OFDM modulation scheme. Any cell in the data symbolswhich has not been designated as a pilot (or as a reserved tone) carriesone of the data cells from the frequency interleaver. The cells aremapped to OFDM carriers.

The PAPR reduction block 8030 can perform a PAPR reduction on inputsignal using various PAPR reduction algorithm in the time domain.

The guard interval insertion block 8040 can insert guard intervals andthe preamble insertion block 8050 can insert preamble in front of thesignal. Details of a structure of the preamble will be described later.The other system insertion block 8060 can multiplex signals of aplurality of broadcast transmission/reception systems in the time domainsuch that data of two or more different broadcast transmission/receptionsystems providing broadcast services can be simultaneously transmittedin the same RF signal bandwidth. In this case, the two or more differentbroadcast transmission/reception systems refer to systems providingdifferent broadcast services. The different broadcast services may referto a terrestrial broadcast service, mobile broadcast service, etc. Datarelated to respective broadcast services can be transmitted throughdifferent frames.

The DAC block 8070 can convert an input digital signal into an analogsignal and output the analog signal. The signal output from the DACblock 7800 can be transmitted through multiple output antennas accordingto the physical layer profiles. A Tx antenna according to an embodimentof the present invention can have vertical or horizontal polarity.

The above-described blocks may be omitted or replaced by blocks havingsimilar or identical functions according to design.

FIG. 9 illustrates a structure of an apparatus for receiving broadcastsignals for future broadcast services according to an embodiment of thepresent invention.

The apparatus for receiving broadcast signals for future broadcastservices according to an embodiment of the present invention cancorrespond to the apparatus for transmitting broadcast signals forfuture broadcast services, described with reference to FIG. 1.

The apparatus for receiving broadcast signals for future broadcastservices according to an embodiment of the present invention can includea synchronization & demodulation module 9000, a frame parsing module9010, a demapping & decoding module 9020, an output processor 9030 and asignaling decoding module 9040. A description will be given of operationof each module of the apparatus for receiving broadcast signals.

The synchronization & demodulation module 9000 can receive input signalsthrough m Rx antennas, perform signal detection and synchronization withrespect to a system corresponding to the apparatus for receivingbroadcast signals and carry out demodulation corresponding to a reverseprocedure of the procedure performed by the apparatus for transmittingbroadcast signals.

The frame parsing module 9100 can parse input signal frames and extractdata through which a service selected by a user is transmitted. If theapparatus for transmitting broadcast signals performs interleaving, theframe parsing module 9100 can carry out deinterleaving corresponding toa reverse procedure of interleaving. In this case, the positions of asignal and data that need to be extracted can be obtained by decodingdata output from the signaling decoding module 9400 to restorescheduling information generated by the apparatus for transmittingbroadcast signals.

The demapping & decoding module 9200 can convert the input signals intobit domain data and then deinterleave the same as necessary. Thedemapping & decoding module 9200 can perform demapping for mappingapplied for transmission efficiency and correct an error generated on atransmission channel through decoding. In this case, the demapping &decoding module 9200 can obtain transmission parameters necessary fordemapping and decoding by decoding the data output from the signalingdecoding module 9400.

The output processor 9300 can perform reverse procedures of variouscompression/signal processing procedures which are applied by theapparatus for transmitting broadcast signals to improve transmissionefficiency. In this case, the output processor 9300 can acquirenecessary control information from data output from the signalingdecoding module 9400. The output of the output processor 8300corresponds to a signal input to the apparatus for transmittingbroadcast signals and may be MPEG-TSs, IP streams (v4 or v6) and genericstreams.

The signaling decoding module 9400 can obtain PLS information from thesignal demodulated by the synchronization & demodulation module 9000. Asdescribed above, the frame parsing module 9100, demapping & decodingmodule 9200 and output processor 9300 can execute functions thereofusing the data output from the signaling decoding module 9400.

FIG. 10 illustrates a frame structure according to an embodiment of thepresent invention.

FIG. 10 shows an example configuration of the frame types and FRUs in asuper-frame. (a) shows a super frame according to an embodiment of thepresent invention, (b) shows FRU (Frame Repetition Unit) according to anembodiment of the present invention, (c) shows frames of variable PHYprofiles in the FRU and (d) shows a structure of a frame.

A super-frame may be composed of eight FRUs. The FRU is a basicmultiplexing unit for TDM of the frames, and is repeated eight times ina super-frame.

Each frame in the FRU belongs to one of the PHY profiles, (base,handheld, advanced) or FEF. The maximum allowed number of the frames inthe FRU is four and a given PHY profile can appear any number of timesfrom zero times to four times in the FRU (e.g., base, base, handheld,advanced). PHY profile definitions can be extended using reserved valuesof the PHY_PROFILE in the preamble, if required.

The FEF part is inserted at the end of the FRU, if included. When theFEF is included in the FRU, the minimum number of FEFs is 8 in asuper-frame. It is not recommended that FEF parts be adjacent to eachother.

One frame is further divided into a number of OFDM symbols and apreamble. As shown in (d), the frame comprises a preamble, one or moreframe signaling symbols (FSS), normal data symbols and a frame edgesymbol (FES).

The preamble is a special symbol that enables fast Futurecast UTB systemsignal detection and provides a set of basic transmission parameters forefficient transmission and reception of the signal. The detaileddescription of the preamble will be will be described later.

The main purpose of the FSS(s) is to carry the PLS data. For fastsynchronization and channel estimation, and hence fast decoding of PLSdata, the FSS has more dense pilot pattern than the normal data symbol.The FES has exactly the same pilots as the FSS, which enablesfrequency-only interpolation within the FES and temporal interpolation,without extrapolation, for symbols immediately preceding the FES.

FIG. 11 illustrates a signaling hierarchy structure of the frameaccording to an embodiment of the present invention.

FIG. 11 illustrates the signaling hierarchy structure, which is splitinto three main parts: the preamble signaling data 11000, the PLS1 data11010 and the PLS2 data 11020. The purpose of the preamble, which iscarried by the preamble symbol in every frame, is to indicate thetransmission type and basic transmission parameters of that frame. ThePLS1 enables the receiver to access and decode the PLS2 data, whichcontains the parameters to access the DP of interest. The PLS2 iscarried in every frame and split into two main parts: PLS2-STAT data andPLS2-DYN data. The static and dynamic portion of PLS2 data is followedby padding, if necessary.

FIG. 12 illustrates preamble signaling data according to an embodimentof the present invention.

Preamble signaling data carries 21 bits of information that are neededto enable the receiver to access PLS data and trace DPs within the framestructure. Details of the preamble signaling data are as follows:

PHY_PROFILE: This 3-bit field indicates the PHY profile type of thecurrent frame. The mapping of different PHY profile types is given inbelow table 5.

TABLE 5 Value PHY profile 000 Base profile 001 Handheld profile 010Advanced profiled 011~110 Reserved 111 FEF

FFT_SIZE: This 2 bit field indicates the FFT size of the current framewithin a frame-group, as described in below table 6.

TABLE 6 Value FFT size 00 8K FFT 01 16K FFT 10 32K FFT 11 Reserved

GI_FRACTION: This 3 bit field indicates the guard interval fractionvalue in the current super-frame, as described in below table 7.

TABLE 7 Value GI_FRACTION 000 ⅕  001 1/10 010 1/20 011 1/40 100 1/80 101  1/160 110~111 Reserved

EAC_FLAG: This 1 bit field indicates whether the EAC is provided in thecurrent frame. If this field is set to ‘1’, emergency alert service(EAS) is provided in the current frame. If this field set to ‘0’, EAS isnot carried in the current frame. This field can be switched dynamicallywithin a super-frame.

PILOT_MODE: This 1-bit field indicates whether the pilot mode is mobilemode or fixed mode for the current frame in the current frame-group. Ifthis field is set to ‘0’, mobile pilot mode is used. If the field is setto ‘1’, the fixed pilot mode is used.

PAPR_FLAG: This 1-bit field indicates whether PAPR reduction is used forthe current frame in the current frame-group. If this field is set tovalue ‘1’, tone reservation is used for PAPR reduction. If this field isset to ‘0’, PAPR reduction is not used.

FRU_CONFIGURE: This 3-bit field indicates the PHY profile typeconfigurations of the frame repetition units (FRU) that are present inthe current super-frame. All profile types conveyed in the currentsuper-frame are identified in this field in all preambles in the currentsuper-frame. The 3-bit field has a different definition for eachprofile, as show in below table 8.

TABLE 8 Current Current Current PHY_PROFILE = PHY_PROFILE = CurrentPHY_PROFILE = ‘001’ ‘010’ PHY_PROFILE = ‘000’ (base) (handheld)(advanced) ‘111’ (FEF) FRU_CONFIGURE = Only base Only handheld Onlyadvanced Only FEF 000 profile profile present profile present presentpresent FRU_CONFIGURE = Handheld profile Base profile Base profile Baseprofile 1XX present present present present FRU_CONFIGURE = AdvancedAdvanced Handheld profile Handheld profile X1X profile profile presentpresent present present FRU_CONFIGURE = FEF FEF FEF Advanced XX1 presentpresent present profile present

RESERVED: This 7-bit field is reserved for future use.

FIG. 13 illustrates PLS1 data according to an embodiment of the presentinvention.

PLS1 data provides basic transmission parameters including parametersrequired to enable the reception and decoding of the PLS2. As abovementioned, the PLS1 data remain unchanged for the entire duration of oneframe-group. The detailed definition of the signaling fields of the PLS1data are as follows:

PREAMBLE_DATA: This 20-bit field is a copy of the preamble signalingdata excluding the EAC_FLAG.

NUM_FRAME_FRU: This 2-bit field indicates the number of the frames perFRU.

PAYLOAD_TYPE: This 3-bit field indicates the format of the payload datacarried in the frame-group. PAYLOAD_TYPE is signaled as shown in table9.

TABLE 9 value Payload type 1XX TS stream is transmitted X1X IP stream istransmitted XX1 GS stream is transmitted

NUM_FSS: This 2-bit field indicates the number of FSS symbols in thecurrent frame.

SYSTEM_VERSION: This 8-bit field indicates the version of thetransmitted signal format. The SYSTEM_VERSION is divided into two 4-bitfields, which are a major version and a minor version.

Major version: The MSB four bits of SYSTEM_VERSION field indicate majorversion information. A change in the major version field indicates anonbackward-compatible change. The default value is ‘0000’. For theversion described in this standard, the value is set to ‘0000’.

Minor version: The LSB four bits of SYSTEM_VERSION field indicate minorversion information. A change in the minor version field isbackward-compatible.

CELL_ID: This is a 16-bit field which uniquely identifies a geographiccell in an

ATSC network. An ATSC cell coverage area may consist of one or morefrequencies, depending on the number of frequencies used per FuturecastUTB system. If the value of the CELL_ID is not known or unspecified,this field is set to ‘0’.

NETWORK_ID: This is a 16-bit field which uniquely identifies the currentATSC network.

SYSTEM_ID: This 16-bit field uniquely identifies the Futurecast UTBsystem within the ATSC network. The Futurecast UTB system is theterrestrial broadcast system whose input is one or more input streams(TS, IP, GS) and whose output is an RF signal. The Futurecast UTB systemcarries one or more PHY profiles and FEF, if any. The same FuturecastUTB system may carry different input streams and use different RFfrequencies in different geographical areas, allowing local serviceinsertion. The frame structure and scheduling is controlled in one placeand is identical for all transmissions within a Futurecast UTB system.One or more Futurecast UTB systems may have the same SYSTEM_ID meaningthat they all have the same physical layer structure and configuration.

The following loop consists of FRU_PHY_PROFILE, FRU_FRAME_LENGTH,FRU_GI_FRACTION, and RESERVED which are used to indicate the FRUconfiguration and the length of each frame type. The loop size is fixedso that four PHY profiles (including a FEF) are signaled within the FRU.If NUM_FRAME_FRU is less than 4, the unused fields are filled withzeros.

FRU_PHY_PROFILE: This 3-bit field indicates the PHY profile type of the(i+1)^(th) (i is the loop index) frame of the associated FRU. This fielduses the same signaling format as shown in the table 8.

FRU_FRAME_LENGTH: This 2-bit field indicates the length of the(i+1)^(th) frame of the associated FRU. Using FRU_FRAME_LENGTH togetherwith FRU_GI_FRACTION, the exact value of the frame duration can beobtained.

FRU_GI_FRACTION: This 3-bit field indicates the guard interval fractionvalue of the (i+1)^(th) frame of the associated FRU. FRU_GI_FRACTION issignaled according to the table 7.

RESERVED: This 4-bit field is reserved for future use.

The following fields provide parameters for decoding the PLS2 data.

PLS2_FEC_TYPE: This 2-bit field indicates the FEC type used by the PLS2protection. The FEC type is signaled according to table 10. The detailsof the LDPC codes will be described later.

TABLE 10 Content PLS2 FEC type 00 4K-1/4 and 7K-3/10 LDPC codes 01~11Reserved

PLS2_MOD: This 3-bit field indicates the modulation type used by thePLS2. The modulation type is signaled according to table 11.

TABLE 11 Value PLS2_MODE 000 BPSK 001 QPSK 010 QAM-16 011 NUQ-64 100~111Reserved

PLS2_SIZE_CELL: This 15-bit field indicates C_(total) _(_) _(parttal)_(_) _(block), the size (specified as the number of QAM cells) of thecollection of full coded blocks for PLS2 that is carried in the currentframe-group. This value is constant during the entire duration of thecurrent frame-group.

PLS2_STAT_SIZE_BIT: This 14-bit field indicates the size, in bits, ofthe PLS2-STAT for the current frame-group. This value is constant duringthe entire duration of the current frame-group.

PLS2_DYN_SIZE_BIT: This 14-bit field indicates the size, in bits, of thePLS2-DYN for the current frame-group. This value is constant during theentire duration of the current frame-group.

PLS2_REP_FLAG: This 1-bit flag indicates whether the PLS2 repetitionmode is used in the current frame-group. When this field is set to value‘1’, the PLS2 repetition mode is activated. When this field is set tovalue ‘0’, the PLS2 repetition mode is deactivated.

PLS2_REP_SIZE_CELL: This 15-bit field indicates C_(total) _(_)_(parttial) _(_) _(block), the size (specified as the number of QAMcells) of the collection of partial coded blocks for PLS2 carried inevery frame of the current frame-group, when PLS2 repetition is used. Ifrepetition is not used, the value of this field is equal to 0. Thisvalue is constant during the entire duration of the current frame-group.

PLS2_NEXT_FEC_TYPE: This 2-bit field indicates the FEC type used forPLS2 that is carried in every frame of the next frame-group. The FECtype is signaled according to the table 10.

PLS2_NEXT_MOD: This 3-bit field indicates the modulation type used forPLS2 that is carried in every frame of the next frame-group. Themodulation type is signaled according to the table 11.

PLS2_NEXT_REP_FLAG: This 1-bit flag indicates whether the PLS2repetition mode is used in the next frame-group. When this field is setto value ‘1’, the PLS2 repetition mode is activated. When this field isset to value ‘0’, the PLS2 repetition mode is deactivated.

PLS2_NEXT_REP_SIZE_CELL: This 15-bit field indicates C_(total) _(_)_(full) _(_) _(block), The size (specified as the number of QAM cells)of the collection of full coded blocks for PLS2 that is carried in everyframe of the next frame-group, when PLS2 repetition is used. Ifrepetition is not used in the next frame-group, the value of this fieldis equal to 0. This value is constant during the entire duration of thecurrent frame-group.

PLS2_NEXT_REP_STAT_SIZE_BIT: This 14-bit field indicates the size, inbits, of the PLS2-STAT for the next frame-group. This value is constantin the current frame-group.

PLS2_NEXT_REP_DYN_SIZE_BIT: This 14-bit field indicates the size, inbits, of the PLS2-DYN for the next frame-group. This value is constantin the current frame-group.

PLS2_AP_MODE: This 2-bit field indicates whether additional parity isprovided for PLS2 in the current frame-group. This value is constantduring the entire duration of the current frame-group. The below table12 gives the values of this field. When this field is set to ‘00’,additional parity is not used for the PLS2 in the current frame-group.

TABLE 12 Value PLS2-AP mode 00 AP is not provided 01 AP1 mode 10~11Reserved

PLS2_AP_SIZE_CELL: This 15-bit field indicates the size (specified asthe number of QAM cells) of the additional parity bits of the PLS2. Thisvalue is constant during the entire duration of the current frame-group.

PLS2_NEXT_AP_MODE: This 2-bit field indicates whether additional parityis provided for PLS2 signaling in every frame of next frame-group. Thisvalue is constant during the entire duration of the current frame-group.The table 12 defines the values of this field

PLS2_NEXT_AP_SIZE_CELL: This 15-bit field indicates the size (specifiedas the number of QAM cells) of the additional parity bits of the PLS2 inevery frame of the next frame-group. This value is constant during theentire duration of the current frame-group.

RESERVED: This 32-bit field is reserved for future use.

CRC_32: A 32-bit error detection code, which is applied to the entirePLS1 signaling.

FIG. 14 illustrates PLS2 data according to an embodiment of the presentinvention.

FIG. 14 illustrates PLS2-STAT data of the PLS2 data. The PLS2-STAT dataare the same within a frame-group, while the PLS2-DYN data provideinformation that is specific for the current frame.

The details of fields of the PLS2-STAT data are as follows:

FIC_FLAG: This 1-bit field indicates whether the FIC is used in thecurrent frame-group. If this field is set to ‘1’, the FIC is provided inthe current frame. If this field set to ‘0’, the FIC is not carried inthe current frame. This value is constant during the entire duration ofthe current frame-group.

AUX_FLAG: This 1-bit field indicates whether the auxiliary stream(s) isused in the current frame-group. If this field is set to ‘1’, theauxiliary stream is provided in the current frame. If this field set to‘0’, the auxiliary stream is not carried in the current frame. Thisvalue is constant during the entire duration of current frame-group.

NUM_DP: This 6-bit field indicates the number of DPs carried within thecurrent frame. The value of this field ranges from 1 to 64, and thenumber of DPs is NUM_DP+1.

DP_ID: This 6-bit field identifies uniquely a DP within a PHY profile.

DP_TYPE: This 3-bit field indicates the type of the DP. This is signaledaccording to the below table 13.

TABLE 13 Value DP Type 000 DP Type 1 001 DP Type 2 010~111 reserved

DP_GROUP_ID: This 8-bit field identifies the DP group with which thecurrent DP is associated. This can be used by a receiver to access theDPs of the service components associated with a particular service,which will have the same DP_GROUP_ID.

BASE_DP_ID: This 6-bit field indicates the DP carrying service signalingdata (such as PSI/SI) used in the Management layer. The DP indicated byBASE_DP_ID may be either a normal DP carrying the service signaling dataalong with the service data or a dedicated DP carrying only the servicesignaling data

DP_FEC_TYPE: This 2-bit field indicates the FEC type used by theassociated DP. The FEC type is signaled according to the below table 14.

TABLE 14 Value FEC_TYPE 00 16K LDPC 01 64K LDPC 10~11 Reserved

DP_COD: This 4-bit field indicates the code rate used by the associatedDP. The code rate is signaled according to the below table 15.

TABLE 15 Value Code rate 0000 5/15 0001 6/15 0010 7/15 0011 8/15 01009/15 0101 10/15  0110 11/15  0111 12/15  1000 13/15  1001~1111 Reserved

DP_MOD: This 4-bit field indicates the modulation used by the associatedDP. The modulation is signaled according to the below table 16.

TABLE 16 Value Modulation 0000 QPSK 0001 QAM-16 0010 NUQ-64 0011 NUQ-2560100 NUQ-1024 0101 NUC-16 0110 NUC-64 0111 NUC-256 1000 NUC-10241001~1111 reserved

DP_SSD_FLAG: This 1-bit field indicates whether the SSD mode is used inthe associated DP. If this field is set to value ‘1’, SSD is used. Ifthis field is set to value ‘0’, SSD is not used.

The following field appears only if PHY_PROFILE is equal to ‘010’, whichindicates the advanced profile:

DP_MIMO: This 3-bit field indicates which type of MIMO encoding processis applied to the associated DP. The type of MIMO encoding process issignaled according to the table 17.

TABLE 17 Value MIMO encoding 000 FR-SM 001 FRFD-SM 010~111 reserved

DP_TI_TYPE: This 1-bit field indicates the type of time-interleaving. Avalue of ‘0’ indicates that one TI group corresponds to one frame andcontains one or more TI-blocks. A value of ‘1’ indicates that one TIgroup is carried in more than one frame and contains only one TI-block.

DP_TI_LENGTH: The use of this 2-bit field (the allowed values are only1, 2, 4, 8) is determined by the values set within the DP_TI_TYPE fieldas follows:

If the DP_TI_TYPE is set to the value ‘1’, this field indicates P₁, thenumber of the frames to which each TI group is mapped, and there is oneTI-block per TI group (N_(TI)=1). The allowed P₁ values with 2-bit fieldare defined in the below table 18.

If the DP_TI_TYPE is set to the value ‘0’, this field indicates thenumber of TI-blocks N_(TI) per TI group, and there is one TI group perframe (P₁=1). The allowed P₁ values with 2-bit field are defined in thebelow table 18.

TABLE 18 2-bit field P_(I) N_(TI) 00 1 1 01 2 2 10 4 3 11 8 4

DP_FRAME_INTERVAL: This 2-bit field indicates the frame interval(I_(JUMP)) within the frame-group for the associated DP and the allowedvalues are 1, 2, 4, 8 (the corresponding 2-bit field is ‘00’, ‘01’,‘10’, or ‘11’, respectively). For DPs that do not appear every frame ofthe frame-group, the value of this field is equal to the intervalbetween successive frames. For example, if a DP appears on the frames 1,5, 9, 13, etc., this field is set to ‘4’. For DPs that appear in everyframe, this field is set to ‘1’.

DP_TI_BYPASS: This 1-bit field determines the availability of timeinterleaver. If time interleaving is not used for a DP, it is set to‘1’. Whereas if time interleaving is used it is set to ‘0’.

DP_FIRST_FRAME_IDX: This 5-bit field indicates the index of the firstframe of the super-frame in which the current DP occurs. The value ofDP_FIRST_FRAME_IDX ranges from 0 to 31

DP_NUM_BLOCK_MAX: This 10-bit field indicates the maximum value ofDP_NUM_BLOCKS_for this DP. The value of this field has the same range asDP_NUM_BLOCKS.

DP_PAYLOAD_TYPE: This 2-bit field indicates the type of the payload datacarried by the given DP. DP_PAYLOAD_TYPE is signaled according to thebelow table 19.

TABLE 19 Value Payload Type 00 TS. 01 IP 10 GS 11 reserved

DP_INBAND_MODE: This 2-bit field indicates whether the current DPcarries in-band signaling information. The in-band signaling type issignaled according to the below table 20.

TABLE 20 Value In-band mode 00 In-band signaling is not carried. 01INBAND-PLS is carried only 10 INBAND-ISSY is carried only 11 INBAND-PLSand INBAND-ISSY are carried

DP_PROTOCOL_TYPE: This 2-bit field indicates the protocol type of thepayload carried by the given DP. It is signaled according to the belowtable 21 when input payload types are selected.

TABLE 21 If DP_PAYLOAD_TYPE If DP_PAYLOAD_TYPE If DP_PAYLOAD_TYPE ValueIs TS Is IP Is GS 00 MPEG2-TS IPv4 (Note) 01 Reserved IPv6 Reserved 10Reserved Reserved Reserved 11 Reserved Reserved Reserved

DP_CRC_MODE: This 2-bit field indicates whether CRC encoding is used inthe Input Formatting block. The CRC mode is signaled according to thebelow table 22.

TABLE 22 Value CRC mode 00 Not used 01 CRC-8 10 CRC-16 11 CRC-32

DNP_MODE: This 2-bit field indicates the null-packet deletion mode usedby the associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). DNP_MODEis signaled according to the below table 23. If DP_PAYLOAD_TYPE is notTS (‘00’), DNP_MODE is set to the value ‘00’.

TABLE 23 Value Null-packet deletion mode 00 Not used 01 DNP-NORMAL 10DNP-OFFSET 11 reserved

ISSY_MODE: This 2-bit field indicates the ISSY mode used by theassociated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). The ISSY_MODE issignaled according to the below table 24 If DP_PAYLOAD_TYPE is not TS(‘00’), ISSY_MODE is set to the value ‘00’.

TABLE 24 Value ISSY mode 00 Not used 01 ISSY-UP 10 ISSY-BBF 11 reserved

HC_MODE_TS: This 2-bit field indicates the TS header compression modeused by the associated DP when DP_PAYLOAD_TYPE is set to TS (‘00’). The

HC_MODE_TS is signaled according to the below table 25.

TABLE 25 Value Header compression mode 00 HC_MODE_TS 1 01 HC_MODE_TS 210 HC_MODE_TS 3 11 HC_MODE_TS 4

HC_MODE_IP: This 2-bit field indicates the IP header compression modewhen DP_PAYLOAD_TYPE is set to IP (‘01’). The HC_MODE_IP is signaledaccording to the below table 26.

TABLE 26 Value Header compression mode 00 No compression 01 HC_MODE_IP 110~11 reserved

PID: This 13-bit field indicates the PID number for TS headercompression when DP_PAYLOAD_TYPE is set to TS (‘00’) and HC_MODE_TS isset to ‘01’ or ‘10’.

RESERVED: This 8-bit field is reserved for future use.

The following field appears only if FIC_FLAG is equal to ‘1’:

FIC_VERSION: This 8-bit field indicates the version number of the FIC.

FIC_LENGTH_BYTE: This 13-bit field indicates the length, in bytes, ofthe FIC.

RESERVED: This 8-bit field is reserved for future use.

The following field appears only if AUX_FLAG is equal to ‘1’:

NUM_AUX: This 4-bit field indicates the number of auxiliary streams.Zero means no auxiliary streams are used.

AUX_CONFIG_RFU: This 8-bit field is reserved for future use.

AUX_STREAM_TYPE: This 4-bit is reserved for future use for indicatingthe type of the current auxiliary stream.

AUX_PRIVATE_CONFIG: This 28-bit field is reserved for future use forsignaling auxiliary streams.

FIG. 15 illustrates PLS2 data according to another embodiment of thepresent invention.

FIG. 15 illustrates PLS2-DYN data of the PLS2 data. The values of thePLS2-DYN data may change during the duration of one frame-group, whilethe size of fields remains constant.

The details of fields of the PLS2-DYN data are as follows:

FRAME_INDEX: This 5-bit field indicates the frame index of the currentframe within the super-frame. The index of the first frame of thesuper-frame is set to ‘0’.

PLS_CHANGE_COUNTER: This 4-bit field indicates the number ofsuper-frames ahead where the configuration will change. The nextsuper-frame with changes in the configuration is indicated by the valuesignaled within this field. If this field is set to the value ‘0000’, itmeans that no scheduled change is foreseen: e.g., value ‘1’ indicatesthat there is a change in the next super-frame.

FIC_CHANGE_COUNTER: This 4-bit field indicates the number ofsuper-frames ahead where the configuration (i.e., the contents of theFIC) will change. The next super-frame with changes in the configurationis indicated by the value signaled within this field. If this field isset to the value ‘0000’, it means that no scheduled change is foreseen:e.g. value ‘0001’ indicates that there is a change in the nextsuper-frame.

RESERVED: This 16-bit field is reserved for future use.

The following fields appear in the loop over NUM_DP, which describe theparameters associated with the DP carried in the current frame.

DP_ID: This 6-bit field indicates uniquely the DP within a PHY profile.

DP_START: This 15-bit (or 13-bit) field indicates the start position ofthe first of the DPs using the DPU addressing scheme. The DP_START fieldhas differing length according to the PHY profile and FFT size as shownin the below table 27.

TABLE 27 DP_START field size PHY profile 64K 16K Base 13 bit 15 bitHandheld — 13 bit Advanced 13 bit 15 bit

DP_NUM_BLOCK: This 10-bit field indicates the number of FEC blocks inthe current TI group for the current DP. The value of DP_NUM_BLOCKranges from 0 to 1023

RESERVED: This 8-bit field is reserved for future use.

The following fields indicate the FIC parameters associated with theEAC.

EAC_FLAG: This 1-bit field indicates the existence of the EAC in thecurrent frame.

This bit is the same value as the EAC_FLAG in the preamble.

EAS_WAKE_UP_VERSION_NUM: This 8-bit field indicates the version numberof a wake-up indication.

If the EAC_FLAG field is equal to ‘1’, the following 12 bits areallocated for EAC_LENGTH_BYTE_field. If the EAC_FLAG field is equal to‘0’, the following 12 bits are allocated for EAC_COUNTER.

EAC_LENGTH_BYTE: This 12-bit field indicates the length, in byte, of theEAC.

EAC_COUNTER: This 12-bit field indicates the number of the frames beforethe frame where the EAC arrives.

The following field appears only if the AUX_FLAG field is equal to ‘ l’:

AUX_PRIVATE_DYN: This 48-bit field is reserved for future use forsignaling auxiliary streams. The meaning of this field depends on thevalue of AUX_STREAM_TYPE in the configurable PLS2-STAT.

CRC_32: A 32-bit error detection code, which is applied to the entirePLS2.

FIG. 16 illustrates a logical structure of a frame according to anembodiment of the present invention.

As above mentioned, the PLS, EAC, FIC, DPs, auxiliary streams and dummycells are mapped into the active carriers of the OFDM symbols in theframe. The PLS1 and PLS2 are first mapped into one or more FSS(s). Afterthat, EAC cells, if any, are mapped immediately following the PLS field,followed next by FIC cells, if any. The DPs are mapped next after thePLS or EAC, FIC, if any. Type 1 DPs follows first, and Type 2 DPs next.The details of a type of the DP will be described later. In some case,DPs may carry some special data for EAS or service signaling data. Theauxiliary stream or streams, if any, follow the DPs, which in turn arefollowed by dummy cells. Mapping them all together in the abovementioned order, i.e. PLS, EAC, FIC, DPs, auxiliary streams and dummydata cells exactly fill the cell capacity in the frame.

FIG. 17 illustrates PLS mapping according to an embodiment of thepresent invention.

PLS cells are mapped to the active carriers of FSS(s). Depending on thenumber of cells occupied by PLS, one or more symbols are designated asFSS(s), and the number of FSS(s) N_(FSS) is signaled by NUM_FSS in PLS1.The FSS is a special symbol for carrying PLS cells. Since robustness andlatency are critical issues in the PLS, the FSS(s) has higher density ofpilots allowing fast synchronization and frequency-only interpolationwithin the FSS.

PLS cells are mapped to active carriers of the N_(FSS) FSS(s) in atop-down manner as shown in an example in FIG. 17. The PLS1 cells aremapped first from the first cell of the first FSS in an increasing orderof the cell index. The PLS2 cells follow immediately after the last cellof the PLS1 and mapping continues downward until the last cell index ofthe first FSS. If the total number of required PLS cells exceeds thenumber of active carriers of one FSS, mapping proceeds to the next FSSand continues in exactly the same manner as the first FSS.

After PLS mapping is completed, DPs are carried next. If EAC, FIC orboth are present in the current frame, they are placed between PLS and“normal” DPs.

FIG. 18 illustrates EAC mapping according to an embodiment of thepresent invention.

EAC is a dedicated channel for carrying EAS messages and links to theDPs for EAS. EAS support is provided but EAC itself may or may not bepresent in every frame. EAC, if any, is mapped immediately after thePLS2 cells. EAC is not preceded by any of the FIC, DPs, auxiliarystreams or dummy cells other than the PLS cells. The procedure ofmapping the EAC cells is exactly the same as that of the PLS.

The EAC cells are mapped from the next cell of the PLS2 in increasingorder of the cell index as shown in the example in FIG. 18. Depending onthe EAS message size, EAC cells may occupy a few symbols, as shown inFIG. 18.

EAC cells follow immediately after the last cell of the PLS2, andmapping continues downward until the last cell index of the last FSS. Ifthe total number of required EAC cells exceeds the number of remainingactive carriers of the last FSS mapping proceeds to the next symbol andcontinues in exactly the same manner as FSS(s). The next symbol formapping in this case is the normal data symbol, which has more activecarriers than a FSS.

After EAC mapping is completed, the FIC is carried next, if any exists.If FIC is not transmitted (as signaled in the PLS2 field), DPs followimmediately after the last cell of the EAC.

FIG. 19 illustrates FIC mapping according to an embodiment of thepresent invention.

(a) shows an example mapping of FIC cell without EAC and (b) shows anexample mapping of FIC cell with EAC.

FIC is a dedicated channel for carrying cross-layer information toenable fast service acquisition and channel scanning. This informationprimarily includes channel binding information between DPs and theservices of each broadcaster. For fast scan, a receiver can decode FICand obtain information such as broadcaster ID, number of services, andBASE_DP_ID. For fast service acquisition, in addition to FIC, base DPcan be decoded using BASE_DP_ID. Other than the content it carries, abase DP is encoded and mapped to a frame in exactly the same way as anormal DP. Therefore, no additional description is required for a baseDP. The FIC data is generated and consumed in the Management Layer. Thecontent of FIC data is as described in the Management Layerspecification.

The FIC data is optional and the use of FIC is signaled by the FIC_FLAGparameter in the static part of the PLS2. If FIC is used, FIC_FLAG isset to ‘1’ and the signaling field for FIC is defined in the static partof PLS2. Signaled in this field are FIC_VERSION, and FIC_LENGTH_BYTE.FIC uses the same modulation, coding and time interleaving parameters asPLS2. FIC shares the same signaling parameters such as PLS2_MOD and PLS2FEC. FIC data, if any, is mapped immediately after PLS2 or EAC if any.FIC is not preceded by any normal DPs, auxiliary streams or dummy cells.The method of mapping FIC cells is exactly the same as that of EAC whichis again the same as PLS.

Without EAC after PLS, FIC cells are mapped from the next cell of thePLS2 in an increasing order of the cell index as shown in an example in(a). Depending on the FIC data size, FIC cells may be mapped over a fewsymbols, as shown in (b).

FIC cells follow immediately after the last cell of the PLS2, andmapping continues downward until the last cell index of the last FSS. Ifthe total number of required FIC cells exceeds the number of remainingactive carriers of the last FSS, mapping proceeds to the next symbol andcontinues in exactly the same manner as FSS(s). The next symbol formapping in this case is the normal data symbol which has more activecarriers than a FSS.

If EAS messages are transmitted in the current frame, EAC precedes FIC,and FIC cells are mapped from the next cell of the EAC in an increasingorder of the cell index as shown in (b).

After FIC mapping is completed, one or more DPs are mapped, followed byauxiliary streams, if any, and dummy cells.

FIG. 20 illustrates a type of DP according to an embodiment of thepresent invention.

(a) shows type 1 DP and (b) shows type 2 DP.

After the preceding channels, i.e., PLS, EAC and FIC, are mapped, cellsof the DPs are mapped. A DP is categorized into one of two typesaccording to mapping method:

Type 1 DP: DP is mapped by TDM

Type 2 DP: DP is mapped by FDM

The type of DP is indicated by DP_TYPE field in the static part of PLS2.FIG. 20 illustrates the mapping orders of Type 1 DPs and Type 2 DPs.Type 1 DPs are first mapped in the increasing order of cell index, andthen after reaching the last cell index, the symbol index is increasedby one. Within the next symbol, the DP continues to be mapped in theincreasing order of cell index starting from p=0. With a number of DPsmapped together in one frame, each of the Type 1 DPs are grouped intime, similar to TDM multiplexing of DPs.

Type 2 DPs are first mapped in the increasing order of symbol index, andthen after reaching the last OFDM symbol of the frame, the cell indexincreases by one and the symbol index rolls back to the first availablesymbol and then increases from that symbol index. After mapping a numberof DPs together in one frame, each of the Type 2 DPs are grouped infrequency together, similar to FDM multiplexing of DPs.

Type 1 DPs and Type 2 DPs can coexist in a frame if needed with onerestriction; Type 1 DPs always precede Type 2 DPs. The total number ofOFDM cells carrying Type 1 and Type 2 DPs cannot exceed the total numberof OFDM cells available for transmission of DPs:

Math Figure 2

D _(DP1) +D _(DP2) ≦D _(DP)  [Math. 2]

where DDP1 is the number of OFDM cells occupied by Type 1 DPs, DDP2 isthe number of cells occupied by Type 2 DPs. Since PLS, EAC, FIC are allmapped in the same way as Type 1 DP, they all follow “Type 1 mappingrule”. Hence, overall, Type 1 mapping always precedes Type 2 mapping.

FIG. 21 illustrates DP mapping according to an embodiment of the presentinvention.

(a) shows an addressing of OFDM cells for mapping type 1 DPs and (b)shows an an addressing of OFDM cells for mapping for type 2 DPs.

Addressing of OFDM cells for mapping Type 1 DPs (0, . . . , DDP11) isdefined for the active data cells of Type 1 DPs. The addressing schemedefines the order in which the cells from the TIs for each of the Type 1DPs are allocated to the active data cells. It is also used to signalthe locations of the DPs in the dynamic part of the PLS2.

Without EAC and FIC, address 0 refers to the cell immediately followingthe last cell carrying PLS in the last FSS. If EAC is transmitted andFIC is not in the corresponding frame, address 0 refers to the cellimmediately following the last cell carrying EAC. If FIC is transmittedin the corresponding frame, address 0 refers to the cell immediatelyfollowing the last cell carrying FIC. Address 0 for Type 1 DPs can becalculated considering two different cases as shown in (a). In theexample in (a), PLS, EAC and FIC are assumed to be all transmitted.Extension to the cases where either or both of EAC and FIC are omittedis straightforward. If there are remaining cells in the FSS aftermapping all the cells up to FIC as shown on the left side of (a).

Addressing of OFDM cells for mapping Type 2 DPs (0, . . . , DDP21) isdefined for the active data cells of Type 2 DPs. The addressing schemedefines the order in which the cells from the TIs for each of the Type 2DPs are allocated to the active data cells. It is also used to signalthe locations of the DPs in the dynamic part of the PLS2.

Three slightly different cases are possible as shown in (b). For thefirst case shown on the left side of (b), cells in the last FSS areavailable for Type 2 DP mapping. For the second case shown in themiddle, FIC occupies cells of a normal symbol, but the number of FICcells on that symbol is not larger than C_(FSS). The third case, shownon the right side in (b), is the same as the second case except that thenumber of FIC cells mapped on that symbol exceeds C_(FSS).

The extension to the case where Type 1 DP(s) precede Type 2 DP(s) isstraightforward since PLS, EAC and FIC follow the same “Type 1 mappingrule” as the Type 1 DP(s).

A data pipe unit (DPU) is a basic unit for allocating data cells to a DPin a frame.

A DPU is defined as a signaling unit for locating DPs in a frame. A CellMapper 7010 may map the cells produced by the TIs for each of the DPs. ATime interleaver 5050 outputs a series of TI-blocks and each TI-blockcomprises a variable number of XFECBLOCKs which is in turn composed of aset of cells. The number of cells in an XFECBLOCK, N_(cells), isdependent on the FECBLOCK size, N_(ldpc), and the number of transmittedbits per constellation symbol. A DPU is defined as the greatest commondivisor of all possible values of the number of cells in a XFECBLOCK,N_(cells), supported in a given PHY profile. The length of a DPU incells is defined as L_(DPU). Since each PHY profile supports differentcombinations of FECBLOCK size and a different number of bits perconstellation symbol, L_(DPU) is defined on a PHY profile basis.

FIG. 22 illustrates an FEC structure according to an embodiment of thepresent invention.

FIG. 22 illustrates an FEC structure according to an embodiment of thepresent invention before bit interleaving. As above mentioned, Data FECencoder may perform the FEC encoding on the input BBF to generateFECBLOCK procedure using outer coding (BCH), and inner coding (LDPC).The illustrated FEC structure corresponds to the FECBLOCK. Also, theFECBLOCK and the FEC structure have same value corresponding to a lengthof LDPC codeword.

The BCH encoding is applied to each BBF (K_(bch), bits), and then LDPCencoding is applied to BCH-encoded BBF (K_(ldpc) bits=N_(bch) bits) asillustrated in FIG. 22.

The value of N_(ldpc) is either 64800 bits (long FECBLOCK) or 16200 bits(short FECBLOCK).

The below table 28 and table 29 show FEC encoding parameters for a longFECBLOCK and a short FECBLOCK, respectively.

TABLE 28 BCH error correction LDPC Rate N_(ldpc) K_(ldpc) K_(bch)capability N_(bch) − K_(bch) 5/15 64800 21600 21408 12 192 6/15 2592025728 7/15 30240 30048 8/15 34560 34368 9/15 38880 38688 10/15  4320043008 11/15  47520 47328 12/15  51840 51648 13/15  56160 55968

TABLE 29 BCH error correction LDPC Rate N_(ldpc) K_(ldpc) K_(bch)capability N_(bch) − K_(bch) 5/15 16200 5400 5232 12 168 6/15 6480 63127/15 7560 7392 8/15 8640 8472 9/15 9720 9552 10/15  10800 10632 11/15 11880 11712 12/15  12960 12792 13/15  14040 13872

The details of operations of the BCH encoding and LDPC encoding are asfollows:

A 12-error correcting BCH code is used for outer encoding of the BBF.The BCH generator polynomial for short FECBLOCK and long FECBLOCK areobtained by multiplying together all polynomials.

LDPC code is used to encode the output of the outer BCH encoding. Togenerate a completed B_(ldpc) (FECBLOCK), P_(ldpc) (parity bits) isencoded systematically from each I_(ldpc) (BCH-encoded BBF), andappended to I_(ldpc). The completed B_(ldpc) (FECBLOCK) are expressed asfollow Math figure.

Math Figure 3

B _(ldpc) =[I _(ldpc) P _(ldpc) ]=[i ₀ ,i ₁ , . . . ,i _(K) _(ldpc) ⁻¹,p ₀ ,p ₁ , . . . ,p _(N) _(ldpc) _(−K) _(ldpc) ⁻¹]  [Math. 3]

The parameters for long FECBLOCK and short FECBLOCK are given in theabove table 28 and 29, respectively.

The detailed procedure to calculate N_(ldpc)−K_(ldpc) parity bits forlong FECBLOCK, is as follows:

1) Initialize the parity bits,

Math Figure 4

p ₀ =p ₁ =p ₂ = . . . =p _(N) _(ldpc) _(−K) _(ldpc) ⁻¹=0  [Math. 4]

2) Accumulate the first information bit −i₀, at parity bit addressesspecified in the first row of an addresses of parity check matrix. Thedetails of addresses of parity check matrix will be described later. Forexample, for rate 13/15:

Math Figure 5

p ₉₈₃ =p ₉₈₃ ⊕i ₀ p ₂₈₁₅ =p ₂₈₁₅ ⊕i ₀

p ₄₈₃₇ =p ₄₈₃₇ ⊕i ₀ p ₄₉₈₉ =p ₄₉₈₉ ⊕i ₀

p ₅₁₃₀ =p ₆₁₃₃ ⊕i ₀ p ₆₄₅₈ =p ₆₄₅₈ ⊕i ₀

p ₆₉₂₁ =p ₆₉₂₁ ⊕i ₀ p ₆₀₇₄ =p ₆₉₇₄ ⊕i ₀

p ₇₅₇₂ =p ₇₅₇₂ ⊕i ₀ p ₈₂₆₀ =p ₈₂₆₀ ⊕i ₀

p ₈₄₉₆ =p ₈₄₉₆ ⊕i ₀  [Math. 5]

3) For the next 359 information bits, i_(s), s=1, 2, . . . , 359accumulate i₅ at parity bit addresses using following Math figure.

Math Figure 6

{x+(s mod 360)×Q _(ldpc)} mod(N _(ldpc) −K _(ldpc))  [Math. 6]

where x denotes the address of the parity bit accumulator correspondingto the first bit i₀, and Q_(ldpc), is a code rate dependent constantspecified in the addresses of parity check matrix. Continuing with theexample, Q_(ldpc)=24 for rate 13/15, so for information bit i₁, thefollowing operations are performed:

Math Figure 7

p ₁₀₀₇ =p ₁₀₀₇ ⊕i ₁ p ₂₈₃₉ =p ₂₈₃₉ ⊕i ₁

p ₄₈₆₁ =p ₄₈₆₁ ⊕i ₁ p ₅₀₁₃ =p ₅₀₁₃ ⊕i ₁

p ₆₁₆₂ =p ₆₁₆₂ ⊕i ₁ p ₆₄₈₂ =p ₆₄₈₂ ⊕i ₁

p ₆₉₄₅ =p ₆₉₄₅ ⊕i ₁ p ₆₉₉₈ =p ₆₉₉₈ ⊕i ₁

p ₇₅₉₆ =p ₇₅₉₆ ⊕i ₁ p ₈₂₈₄ =p ₈₂₈₄ ⊕i ₁

p ₈₅₂₀ =p ₈₅₂₀ ⊕i ₁  [Math. 7]

4) For the 361st information bit i₃₆₀, the addresses of the parity bitaccumulators are given in the second row of the addresses of paritycheck matrix. In a similar manner the addresses of the parity bitaccumulators for the following 359 information bits i₅, s=361, 362, . .. , 719 are obtained using the Math FIG. 6, where x denotes the addressof the parity bit accumulator corresponding to the information bit i₃₆₀,i.e., the entries in the second row of the addresses of parity checkmatrix.

5) In a similar manner, for every group of 360 new information bits, anew row from addresses of parity check matrixes used to find theaddresses of the parity bit accumulators.

After all of the information bits are exhausted, the final parity bitsare obtained as follows:

6) Sequentially perform the following operations starting with i=1

Math Figure 8

p _(i) =p _(i) ⊕p _(i−1) , i=1,2, . . . ,N _(lpdc) −K _(lpdc)−1  [Math.8]

where final content of p_(i), i=0, 1, . . . N_(lpdc)−K_(lpdc)−1 is equalto the parity bit p_(i).

TABLE 30 Code Rate Q_(ldpc) 5/15 120 6/15 108 7/15 96 8/15 84 9/15 7210/15  60 11/15  48 12/15  36 13/15  24

This LDPC encoding procedure for a short FECBLOCK is in accordance witht LDPC encoding procedure for the long FECBLOCK, except replacing thetable 30 with table 31, and replacing the addresses of parity checkmatrix for the long FECBLOCK with the addresses of parity check matrixfor the short FECBLOCK.

TABLE 31 Code Rate Q_(ldpc) 5/15 30 6/15 27 7/15 24 8/15 21 9/15 1810/15  15 11/15  12 12/15  9 13/15  6

FIG. 23 illustrates a bit interleaving according to an embodiment of thepresent invention.

The outputs of the LDPC encoder are bit-interleaved, which consists ofparity interleaving followed by Quasi-Cyclic Block (QCB) interleavingand inner-group interleaving.

(a) shows Quasi-Cyclic Block (QCB) interleaving and (b) showsinner-group interleaving.

The FECBLOCK may be parity interleaved. At the output of the parityinterleaving, the LDPC codeword consists of 180 adjacent QC blocks in along FECBLOCK and 45 adjacent QC blocks in a short FECBLOCK. Each QCblock in either a long or short FECBLOCK consists of 360 bits. Theparity interleaved LDPC codeword is interleaved by QCB interleaving. Theunit of QCB interleaving is a QC block. The QC blocks at the output ofparity interleaving are permutated by QCB interleaving as illustrated inFIG. 23, where N_(cells)=64800/η_(mod) or 16200/η_(mod) according to theFECBLOCK length. The QCB interleaving pattern is unique to eachcombination of modulation type and LDPC code rate.

After QCB interleaving, inner-group interleaving is performed accordingto modulation type and order (η_(mod)) which is defined in the belowtable 32. The number of QC blocks for one inner-group, N_(QCB) _(_)_(IG), is also defined.

TABLE 32 Modulation type η_(mod) N_(QCB) _(—) _(IG) QAM-16 4 2 NUC-16 44 NUQ-64 6 3 NUC-64 6 6 NUQ-256 8 4 NUC-256 8 8 NUQ-1024 10 5 NUC-102410 10

The inner-group interleaving process is performed with N_(QCB) _(_)_(IG) QC blocks of the QCB interleaving output Inner-group interleavinghas a process of writing and reading the bits of the inner-group using360 columns and N_(QCB) _(_) _(IG) rows. In the write operation, thebits from the QCB interleaving output are written row-wise. The readoperation is performed column-wise to read out m bits from each row,where m is equal to 1 for NUC and 2 for NUQ.

FIG. 24 illustrates a cell-word demultiplexing according to anembodiment of the present invention.

(a) shows a cell-word demultiplexing for 8 and 12 bpcu MIMO and (b)shows a cell-word demultiplexing for 10 bpcu MIMO.

Each cell word (c_(0,l), c_(1,l), . . . , c_(nmod−1,l)) of the bitinterleaving output is demultiplexed into (d_(1,0,m), d_(1,1,m) . . . ,d_(1,nmod−1,m)) and (d_(2,0,m), d_(2,1,m) . . . , d_(2,nmod−1,m)) asshown in (a), which describes the cell-word demultiplexing process forone XFECBLOCK.

For the 10 bpcu MIMO case using different types of NUQ for MIMOencoding, the Bit Interleaver for NUQ-1024 is re-used. Each cell word(c_(0,l), c_(1,l), . . . , c_(9,l)) of the Bit Interleaver output isdemultiplexed into (d_(1,0,m), d_(1,1, m) . . . , d_(1,3,m)) and(d_(2,0,m), d_(2,1,m) . . . , d_(2,5,m)), as shown in (b).

FIG. 25 illustrates a time interleaving according to an embodiment ofthe present invention.

(a) to (c) show examples of TI mode.

The time interleaver operates at the DP level. The parameters of timeinterleaving (TI) may be set differently for each DP.

The following parameters, which appear in part of the PLS2-STAT data,configure the TI:

DP_TI_TYPE (allowed values: 0 or 1): Represents the TI mode; ‘0’indicates the mode with multiple TI blocks (more than one TI block) perTI group. In this case, one TI group is directly mapped to one frame (nointer-frame interleaving). ‘1’ indicates the mode with only one TI blockper TI group. In this case, the TI block may be spread over more thanone frame (inter-frame interleaving).

DP_TI_LENGTH: If DP_TI_TYPE=‘0’, this parameter is the number of TIblocks N_(TI) per TI group. For DP_TI_TYPE=‘1’, this parameter is thenumber of frames P₁ spread from one TI group.

DP_NUM_BLOCK_MAX (allowed values: 0 to 1023): Represents the maximumnumber of XFECBLOCKs per TI group.

DP_FRAME_INTERVAL (allowed values: 1, 2, 4, 8): Represents the number ofthe frames I_(JUMP) between two successive frames carrying the same DPof a given PHY profile.

DP_TI_BYPASS (allowed values: 0 or 1): If time interleaving is not usedfor a DP, this parameter is set to ‘1’. It is set to ‘0’ if timeinterleaving is used.

Additionally, the parameter DP_NUM_BLOCK from the PLS2-DYN data is usedto represent the number of XFECBLOCKs carried by one TI group of the DP.

When time interleaving is not used for a DP, the following TI group,time interleaving operation, and TI mode are not considered. However,the Delay Compensation block for the dynamic configuration informationfrom the scheduler will still be required. In each DP, the XFECBLOCKsreceived from the SSD/MIMO encoding are grouped into TI groups. That is,each TI group is a set of an integer number of XFECBLOCKs and willcontain a dynamically variable number of XFECBLOCKs. The number ofXFECBLOCKs in the TI group of index n is denoted by N_(xBLOCK) _(_)_(Group)(n) and is signaled as DP_NUM_BLOCK in the PLS2-DYN data. Notethat N_(xBLOCK) _(_) _(Group)(n) may vary from the minimum value of 0 tothe maximum value N_(xBLOCK) _(_) _(Group) _(_) _(MAX) (corresponding toDP_NUM_BLOCK_MAX) of which the largest value is 1023.

Each TI group is either mapped directly onto one frame or spread overP_(I) frames. Each TI group is also divided into more than one TI blocks(N_(TI)), where each TI block corresponds to one usage of timeinterleaver memory. The TI blocks within the TI group may containslightly different numbers of XFECBLOCKs. If the TI group is dividedinto multiple TI blocks, it is directly mapped to only one frame. Thereare three options for time interleaving (except the extra option ofskipping the time interleaving) as shown in the below table 33.

TABLE 33 Modes Descriptions Option-1 Each TI group contains one TI blockand is mapped directly to one frame as shown in (a). This option issignaled in the PLS2-STAT by DP_TI_TYPE = ‘0’ and DP_TI_LENGTH =‘1’(N_(TI) = 1). Option-2 Each TI group contains one TI block and ismapped to more than one frame. (b) shows an example, where one TI groupis mapped to two frames, i.e., DP_TI_LENGTH = ‘2’ (P_(I) = 2) andDP_FRAME_INTERVAL (I_(JUMP) = 2). This provides greater time diversityfor low data-rate services. This option is signaled in the PLS2-STAT byDP_TI_TYPE = ‘1’. Option-3 Each TI group is divided into multiple TIblocks and is mapped directly to one frame as shown in (c). Each TIblock may use full TI memory, so as to provide the maximum bit-rate fora DP. This option is signaled in the PLS2-STAT signaling by DP_TI_TYPE =‘0’ and DP_TI_LENGTH = N_(TI), while P_(I) = 1.

In each DP, the TI memory stores the input XFECBLOCKs (output XFECBLOCKsfrom the SSD/MIMO encoding block). Assume that input XFECBLOCKs aredefined as

(d_(n, s, 0, 0), d_(n, s, 0, 1), … , d_(n, s, 0, N_(cells) − 1), d_(n, s, 1, 0), … , d_(n, s, 1, N_(cells) − 1), … , d_(n, s, N_(xBLOCK _ TI)(n, s) − 1, 0), … , d_(n, s, N_(xBLOCK _ TI)(n, s) − 1, N_(cells) − 1)),

where d_(n,s,r,q) is the qth cell of the rth XFECBLOCK in the sth TIblock of the nth TI group and represents the outputs of SSD and MIMOencodings as follows.

$d_{n,s,r,q} = \{ {\begin{matrix}{f_{n,s,r,q},} & {{the}\mspace{14mu} {output}\mspace{14mu} {of}\mspace{14mu} S\; S\; D\mspace{14mu} \ldots \mspace{14mu} {encoding}} \\{g_{n,s,r,q},} & {{the}\mspace{14mu} {output}\mspace{14mu} {of}\mspace{14mu} M\; I\; M\; O\mspace{14mu} {encoding}}\end{matrix}.} $

In addition, assume that output XFECBLOCKs from the time interleaver aredefined as

(h_(n, s, 0), h_(n, s, 1), … , h_(n, s, i), … , h_(n, s, N_(xBLOCK _ TI)(n, s) × N_(cells) − 1))

where h_(n,s,i) is the ith output cell (for i=0, . . . , N_(xBLOCK) _(_)_(TI)(n,s)×N_(cells)−1) in the sth TI block of the nth TI group.

Typically, the time interleaver will also act as a buffer for DP dataprior to the process of frame building. This is achieved by means of twomemory banks for each DP. The first TI-block is written to the firstbank. The second TI-block is written to the second bank while the firstbank is being read from and so on.

The TI is a twisted row-column block interleaver. For the sth TI blockof the nth TI group, the number of rows N_(r) of a TI memory is equal tothe number of cells N_(cells), i.e., N_(r)=N_(cells) while the number ofcolumns N_(r) is equal to the number N_(xBLOCK) _(_) _(TI)(n,s).

FIG. 26 illustrates the basic operation of a twisted row-column blockinterleaver according to an embodiment of the present invention.

shows a writing operation in the time interleaver and (b) shows areading operation in the time interleaver The first XFECBLOCK is writtencolumn-wise into the first column of the TI memory, and the secondXFECBLOCK is written into the next column, and so on as shown in (a).Then, in the interleaving array, cells are read out diagonal-wise.During diagonal-wise reading from the first row (rightwards along therow beginning with the left-most column) to the last row, N_(r) cellsare read out as shown in (b). In detail, assuming z_(n,s,i)(i=0, . . . ,N_(r)N_(e)) as the TI memory cell position to be read sequentially, thereading process in such an interleaving array is performed bycalculating the row index R_(n,s,i), the column index c, and theassociated twisting parameter T_(n,s,i) as follows expression.

$\begin{matrix}{{MathFigure}\mspace{14mu} 9} & \; \\{{{GENERATE}( {R_{n,s,i},C_{n,s,i}} )} = \{ {{R_{n,s,i} = {{mod}( {i,N_{r}} )}},{T_{n,s,i} = {{mod}( {{S_{shift} \times R_{n,s,i}},N_{c}} )}},{C_{n,s,i} = {{mod}( {{T_{n,s,i} + \lfloor \frac{i}{N_{r}} \rfloor},N_{c}} )}}} \}} & \lbrack {{Math}.\mspace{14mu} 9} \rbrack\end{matrix}$

where

S _(shift)

is a common shift value for the diagonal-wise reading process regardlessof

N _(xBLOCK) _(_) _(TI)(n,s),

and it is determined by

N _(xBLOCK) _(_) _(TI) _(_) _(MAX)

given in the PLS2-STAT as follows expression.

$\begin{matrix}{\mspace{79mu} {{{MathFigure}\mspace{14mu} 10}{\mspace{625mu} \lbrack {{Math}.\mspace{14mu} 10} \rbrack}\mspace{79mu} {for}\{ {\begin{matrix}\begin{matrix}{N_{{xBLOCK\_ TI}{\_ MAX}}^{\prime} =} \\{{N_{{xBLOCK\_ TI}{\_ MAX}} + 1},}\end{matrix} & {{{if}\mspace{11mu} N_{{xBLOCK\_ TI}{\_ MAX}}{mod}\; 2} = 0} \\{{N_{{xBLOCK\_ TI}{\_ MAX}}^{\prime} = N_{{xBLOCK\_ TI}{\_ MAX}}},} & {{{if}\mspace{11mu} N_{{xBLOCK\_ TI}{\_ MAX}}{mod}\; 2} = 1}\end{matrix},\mspace{79mu} {S_{shift} = \frac{N_{{xBLOCK\_ TI}{\_ MAX}}^{\prime} - 1}{2}}} }} & \;\end{matrix}$

As a result, the cell positions to be read are calculated by acoordinate as

z _(n,s,i) =N _(r) C _(n,s,i) +R _(n,s,i)

.

FIG. 27 illustrates an operation of a twisted row-column blockinterleaver according to another embodiment of the present invention.

More specifically, FIG. 27 illustrates the interleaving array in the TImemory for each TI group, including virtual XFECBLOCKs when

N _(xBLOCK) _(_) _(TI)(0,0)=3,

N _(xBLOCK) _(_) _(TI)(1,0)=6,

N _(xBLOCK) _(_) _(TI)(2,0)=5.

The variable number

N _(xBLOCK) _(_) _(TI)(n,s)=N _(r)

will be less than or equal to

N′ _(xBLOCK) _(_) _(TI) _(_) _(MAX).

Thus, in order to achieve a single-memory deinterleaving at the receiverside, regardless of

N _(xBLOCK) _(_) _(TI)(n,s),

the interleaving array for use in a twisted row-column block interleaveris set to the size of

N _(r) ×N _(c) =N _(cells) ×N′ _(xBLOCK) _(_) _(TI) _(_) _(MAX)

by inserting the virtual XFECBLOCKs into the TI memory and the readingprocess is accomplished as follow expression.

$\begin{matrix}{{MathFigure}\mspace{14mu} 11} & \; \\{{p = 0};} & {\lbrack {{Math}.\mspace{14mu} 11} \rbrack \;} \\{{{{{for}\mspace{14mu} i} = 0};{i < {N_{cells}N_{{xBLOCK\_ TI}{\_ MAX}}^{\prime}}};{i = {i + 1}}}\{ {{{GENERATE}( {R_{n,s,i},C_{n,s,i}} )};{V_{i} = {{{N_{r}C_{n,s,j}} + {R_{n,s,j}\mspace{31mu} {{if}\mspace{14mu} V_{i}}}} < {N_{cells}{N_{xBLOCK\_ TI}( {n,s} )}\mspace{31mu} \{ \mspace{45mu} {{Z_{n,s,p} = V_{i}};{p = {p + 1}};}\mspace{45mu} \}}}}} \}} & \;\end{matrix}$

The number of TI groups is set to 3. The option of time interleaver issignaled in the PLS2-STAT data by DP_TI_TYPE=‘0’, DP_FRAME_INTERVAL=‘1’,and DP_TI_LENGTH=‘1’, I_(JUMP)=1, and P₁=1. The number of XFECBLOCKs,each of which has N_(cells)=30 cells, per TI group is signaled in thePLS2-DYN data by N_(xBLOCK) _(_) _(TI)(0,0)=3, N_(xBLOCK) _(_)_(TI)(1,0)=6, and N_(xBLOCK) _(_) _(TI)(2,0)=5, respectively. Themaximum number of XFECBLOCK is signaled in the PLS2-STAT data byN_(xBLOCK) _(_) _(Group) _(_) _(MAX), which leads to

└N _(xBLOCK) _(_) _(Group) _(_) _(MAX) /N _(TI) ┘=N _(xBLOCK) _(_) _(TI)_(_) _(MAX)=6

FIG. 28 illustrates a diagonal-wise reading pattern of a twistedrow-column block interleaver according to an embodiment of the presentinvention.

More specifically FIG. 28 shows a diagonal-wise reading pattern fromeach interleaving array with parameters of

N′ _(xBLOCK) _(_) _(TI) _(_) _(MAX)=7

and S_(shift)=(7−1)/2=3. Note that in the reading process shown aspseudocode above, if

V _(i) ≧N _(cells) N _(xBLOCK) _(_) _(TI)(n,s),

the value of V_(i) is skipped and the next calculated value of V_(i) isused.

FIG. 29 illustrates interlaved XFECBLOCKs from each interleaving arrayaccording to an embodiment of the present invention.

FIG. 29 illustrates the interleaved XFECBLOCKs from each interleavingarray with parameters of

N′ _(xBLCOK) _(_) _(TI) _(_) _(MAX)=7

and S_(shift)=3.

A method for segmenting a file configured to transmit file-basedmultimedia content in a real-time broadcast environment, and consumingthe file segments according to the embodiments of the present inventionwill hereinafter be described in detail.

In more detail, the embodiment provides a data structure fortransmitting the file-based multimedia content in the real-timebroadcast environment. In addition, the embodiment provides a method foridentifying not only segmentation generation information of a fileneeded for transmitting file-based multimedia content but alsoconsumption information in a real-time broadcast environment. Inaddition, the embodiment provides a method for segmenting/generating afile needed for transmitting the file-based multimedia content in areal-time broadcast environment. The embodiment provides a method forsegmenting and consuming the file needed for consuming the file-basedmultimedia content.

FIG. 30 illustrates a data processing time when a File Delivery overUnidirectional Transport (FLUTE) protocol is used.

Recently, hybrid broadcast services in which a broadcast network and theInternet network are combined have been widely used. The hybridbroadcast service may transmit A/V content to the legacy broadcastnetwork, and may transmit additional data related to A/V content overthe Internet. In addition, a service for transmitting some parts of theA/V content may be transmitted over the Internet has recently beenprovided.

Since the A/V content is transmitted over a heterogeneous network, amethod for closely combining A/V content data pieces transmitted over aheterogeneous network and a simple cooperation method are needed. Forthis purpose, a communication transmission method capable of beingsimultaneously applied to the broadcast network and the Internet isneeded.

A representative one of the A/V content transmission methods capable ofbeing commonly applied to the broadcast network and the Internet is touse the file-based multimedia content. The file-based multimedia contenthas superior extensibility, is not dependent upon a transmission (Tx)protocol, and has been widely used using a download scheme based on thelegacy Internet.

A File Delivery over Unidirectional Transport protocol (FLUTE) is aprotocol that is appropriate not only for the interaction between thebroadcast network and the Internet but also for transmission of thefile-based multimedia content of a large-capacity file.

FLUTE is an application for unidirectional file transmission based onALC, and is a protocol in which information regarding files needed forfile transmission or information needed for transmission are defined.According to FLUTE, information needed for file transmission andinformation regarding various attributes of a file to be transmittedhave been transmitted through transmission of FDT (File Delivery Table)instance, and the corresponding file is then transmitted.

ALC (Asynchronous Layered Coding) is a protocol in which it is possibleto control reliability and congestion during a file transmission time inwhich a single transmitter transmits the file to several receivers. ALCis a combination of an FEC Building Block for error control, a WEBRCBuilding Block for congestion control, a Layered Coding Transport (LCT)Building Block for session and channel management, and may construct abuilding block according to the service and necessity.

ALC is used as a content transmission protocol such that it can veryefficiently transmit data to many receivers. In addition, ALC hasunidirectional characteristics, is transmitted in a limited manner asnecessary, does not require specific channel and resources for feedback,and can be used not only in the wireless environmental broadcasting butalso in the satellite environmental broadcasting. Since ALC has nofeedback, the FEC code scheme can be entirely or partially applied forreliability, resulting in implementation of reliable services. Inaddition, an object to be sent is FEC-encoded according to the FECscheme, constructs Tx blocks and additional symbols formed by the FECscheme, and is then transmitted. ALC session may be composed of one ormore channels, and several receivers select a channel of the sessionaccording to the network state and receive a desired object over theselected channel. The receivers can be devoted to receive its owncontent, and are little affected by a state of other receivers or passloss. Therefore, ALC has high stability or can provide a stable contentdownload service using multi-layered transmission.

LCT may support transmission (Tx) levels for a reliable contenttransmission (e.g., FLUTE) protocol and a stream transmission protocol.LCT may provide content and characteristics of the basic information tobe transmitted to the receiver. For example, LCT may include aTreansport Session Identifier (TSI) field, a Transport Object ID (TOI)field, and a Congestion Control Information (CCI) field.

TSI field may include information for identifying the ALC/LCT session.For example, a channel contained in the session may be identified usinga transmitter IP address and a UDP port. TOI field may includeinformation for identifying each file object. CCI field may includeinformation regarding a used or unused state and information regarding aCongestion Control Block. In addition, LCT may provide additionalinformation and FEC-associated information through an extended header.

As described above, the object (e.g., file) is packetized according tothe FLUTE protocol, and is then packetized according to the ALC/LCTscheme. The packetized ALC/LCT data is re-packetized according to theUDP scheme, and the packetized ALC/LCT/UDP data is packetized accordingto the IP scheme, resulting in formation of ALC/LCT/UDP/IP data.

The file-based multimedia content may be transmitted not only to theInternet but also to the broadcast network through the contenttransmission protocol such as LCT. In this case, multimedia contentcomposed of at least one object or file may be transmitted and consumedin units of an object or a file through the LCT. A detailed descriptionthereof will hereinafter be described in detail.

FIG. 30(a) shows a data structure based on the FLUTE protocol. Forexample, the multimedia content may include at least one object. Oneobject may include at least one fragment (Fragment 1 or Fragment 2).

A data processing time needed for the FLUTE protocol is shown in FIG.30(b). In FIG. 30(b), the lowest drawing shows the encoding start andend times at which the broadcast signal transmission apparatus starts orstops encoding of one object, and the highest drawing shows thereproduction start and end times at which the broadcast signal receptionapparatus starts or stops reproduction of one object.

The broadcast signal transmission apparatus may start transmission ofthe object upon after completion of generation of the object includingat least one fragment. Therefore, there occurs a transmission standbytime (D_(t1)) between a start time at which the broadcast signaltransmission apparatus starts to generate the object and another time atwhich the broadcast signal transmission apparatus starts to transmit theobject.

In addition, the broadcast signal reception apparatus stops reception ofthe object including at least one object, and then starts reproductionof the object. Therefore, there occurs a reproduction standby time(D_(r1)) between a start time at which the broadcast signal receptionapparatus starts reception of the object and another time at which thebroadcast signal reception apparatus starts to reproduce the object.

Therefore, a predetermined time corresponding to the sum of atransmission standby time and a reproduction standby time is neededbefore one object is transmitted from the broadcast signal transmissionapparatus and is then reproduced by the broadcast signal receptionapparatus. This means that the broadcast signal reception apparatusrequires a relatively long initial access time to access thecorresponding object.

As described above, since the FLUTE protocol is used, the broadcastsignal transmission apparatus transmits data on an object basis, thebroadcast signal reception apparatus must receive data of one object andmust consume the corresponding object. Therefore, object transmissionbased on the FLUTE protocol is inappropriate for the real-time broadcastenvironment.

FIG. 31 illustrates a Real-Time Object Delivery over UnidirectionalTransport (ROUTE) protocol stack according to an embodiment of thepresent invention.

The next-generation broadcast system supporting the IP-based hybridbroadcasting may include video data, audio data, subtitle data,signaling data, Electronic Service Guide (ESG) data, and/or NRT contentdata.

Video data, audio data, subtitle data, etc. may be encapsulated in theform of ISO Base Media File (hereinafter referred to as ISO BMFF). Forexample, data encapsulated in the form of ISO BMFF may have a of MPEG(Moving Picture Expert Group)—DASH (Dynamic Adaptive Streaming overHTTP) segment or a format of Media Processing Unit (MPU). Then, dataencapsulated in the form of BMFF may be equally transmitted over thebroadcast network or the Internet or may be differently transmittedaccording to attributes of respective transmission networks.

In the case of the broadcast network, data encapsulated in the form ofISO BMFF may be encapsulated in the form of an application layertransport protocol packet supporting real-time object transmission. Forexample, data encapsulated in the form of ISO BMFF may be encapsulatedin the form of ROUTE (Real-Time Object Delivery over UnidirectionalTransport) and MMT transport packet.

Real-Time Object Delivery over Unidirectional Transport (ROUTE) is aprotocol for the delivery of files over IP multicast networks. ROUTEprotocol utilizes Asynchronous Layered Coding (ALC), the base protocoldesigned for massively scalable multicast distribution, Layered CodingTransport (LCT), and other well-known Internet standards.

ROUTE is an enhancement of and functional replacement for FLUTE withadditional features. ROUTE protocol is the reliable delivery of deliveryobjects and associated metadata using LCT packets. The ROUTE protocolmay be used for real-time delivery.

Thereafter, data encapsulated in the form of the application layertransport protocol packet may be packetized according to the IP/UDPscheme. The data packetized by the IP/UDP scheme may be referred to asthe IP/UDP datagram, and the IP/UDP datagram may be loaded on thebroadcast signal and then transmitted.

In the case of the Internet, data encapsulated in the form of ISO BMFFmay be transferred to the receiver according to the streaming scheme.For example, the streaming scheme may include MPEG-DASH.

The signaling data may be transmitted using the following methods.

In the case of the broadcast network, signaling data may be transmittedthrough a specific data pipe (hereinafter referred to as DP) of atransport frame (or frame) applied to a physical layer of thenext-generation broadcast transmission system and broadcast networkaccording to attributes of the signaling data. For example, thesignaling format may be encapsulated in the form of a bitstream orIP/UDP datagram.

In the case of the Internet, the signaling data may be transmitted as aresponse to a request of the receiver.

ESG data and NRT content data may be transmitted using the followingmethods.

In the case of the broadcast network, ESG data and NRT content data maybe encapsulated in the form of an application layer transport protocolpacket. Thereafter, data encapsulated in the form of the applicationlayer transport protocol packet may be transmitted in the same manner asdescribed above.

In the case of the Internet, ESG data and NRT content data may betransmitted as a response to the request of the receiver.

The physical layers (Broadcast PHY and broadband PHY) of the broadcastsignal transmission apparatus according to the embodiment may be shownin FIG. 1. In addition, the physical layers of the broadcast signalreception apparatus may be shown in FIG. 9.

The signaling data and the IP/UDP datagram may be transmitted through aspecific data pipe (hereinafter referred to as DP) of a transport frame(or frame). For example, the input formatting block 1000 may receive thesignaling data and the IP/UDP datagram, each of the signaling data andthe IP/UDP datagram may be demultiplexed into at least one DP. Theoutput processor 9300 may perform the operations opposite to those ofthe input formatting block 1000.

The following description relates to an exemplary case in which dataencapsulated in the form of ISO BMFF is encapsulated in the form ofROUTE transport packet, and a detailed description of the exemplary casewill hereinafter be described in detail.

<Data Structure for Real-Time File Generation and Consumption>

FIG. 32 illustrates a data structure of file-based multimedia contentaccording to an embodiment of the present invention.

The data structure of the file-based multimedia content according to theembodiment is shown in FIG. 32. The term “file-based multimedia content”may indicate multimedia content composed of at least one file.

The multimedia content such as a broadcast program may be composed ofone presentation. The presentation may include at least one object. Forexample, the object may be a file. In addition, the object may includeat least one fragment.

In accordance with the embodiment, the fragment may be a data unitcapable of being independently decoded and reproduced without dependingon the preceding data. For example, the fragment including video datamay begin from an IDR picture, and header data for parsing media datadoes not depend on the preceding fragment. The fragment according to theembodiment may be divided and transmitted in units of at least onetransfer block (TB).

In accordance with the embodiment, the transfer block (TB) may be aminimum data unit capable of being independently and transmitted withoutdepending on the preceding data. In addition, the TB may be asignificant data unit configured in the form of a variable-sized GOP orchunk. For example, the TB may include at least one chunk composed ofthe same media data as in GOP of video data. The term “chunk” mayindicate a segment of the content. In addition, the TB may include atleast one source block.

The TB may include at least one data, and respective data pieces mayhave the same or different media types. For example, the media type mayinclude an audio type and a video type. That is, the TB may also includeone or more data pieces having different media types in the same manneras in the audio and video data.

The fragment according to the embodiment may include a fragment headerand a fragment payload.

The fragment header may include timing information and indexinginformation to parse the above-mentioned chunks. The fragment header maybe comprised of at least one TB. For example, the fragment header may becontained in one TB. In addition, at least one chunk data constructingthe fragment payload may be contained in at least one TB. As describedabove, the fragment header and the fragment payload may be contained inat least one TB.

The TB may be divided into one or more symbols. At least one symbol maybe packetized. For example, the broadcast signal transmission apparatusaccording to the embodiment may packetize at least one symbol into theLCT packet.

The broadcast signal transmission apparatus according to the embodimentmay transmit the packetized data to the broadcast signal receptionapparatus.

FIG. 33 illustrates a media segment structure of MPEG-DASH to which thedata structure is applied.

Referring to FIG. 33, the data structure according to the embodiment isapplied to a media segment of MPEG-DASH.

The broadcast signal transmission apparatus according to the embodimentinclude multimedia contents having a plurality of qualities in theserver, provides the multimedia contents appropriate for the userbroadcast environment and the environment of the broadcast signalreception apparatus, such that it can provide the seamless real-timestreaming service. For example, the broadcast signal transmissionapparatus may provide the real-time streaming service using MPEG-DASH.

The broadcast signal transmission apparatus can dynamically transmitXML-type MPD (Media Presentation Description) and a segment ofbinary-format transmit (Tx) multimedia content to the broadcast signalreception apparatus using the ROUTE protocol according to the broadcastenvironment and the environment of the broadcast signal receptionapparatus.

MPD is comprised of a hierarchical structure, and may include astructural function of each layer and roles of each layer.

The segment may include a media segment. The media segment may be a dataunit having a media-related object format being separated per quality orper time to be transmitted to the broadcast signal reception apparatusso as to support the streaming service. The media segment may includeinformation regarding a media stream, at least one access unit, andinformation regarding a method for accessing Media Presentationcontained in the corresponding segment such as a presentation time orindex. In addition, the media segment may be divided into at least onesubsegment by the segment index.

MPEG-DASH content may include at least one media segment. The mediasegment may include at least one fragment. For example, the fragment maybe the above-mentioned subsegment. As described above, the fragment mayinclude a fragment header and a fragment payload.

The fragment header may include a segment index box (sidx) and a moviefragment box (moof). The segment index box may provide an initialpresentation time of media data present in the corresponding fragment, adata offset, and SAP (Stream Access Points) information. The moviefragment box may include metadata regarding a media data box (mdat). Forexample, the movie fragment box may include timing, indexing, anddecoding information of a media data sample contained in the fragment.

The fragment payload may include the media data box (mdat). The mediadata box (mdat) may include actual media data regarding thecorresponding media constituent elements (video and audio data, etc.).

The encoded media data configured on a chunk basis may be contained inthe media data box (mdat) corresponding to the fragment payload. Asdescribed above, samples corresponding to the same track may becontained in one chunk.

The broadcast signal transmission apparatus may generate at least one TBthrough fragment segmentation. In addition, the broadcast signaltransmission apparatus may include the fragment header and the payloaddata in different TB s so as to discriminate between the fragment headerand the payload data.

In addition, the broadcast signal transmission apparatus may transmit atransfer block (TB) divided on a chunk basis so as to segment/transmitdata contained in the fragment payload. That is, the broadcast signaltransmission apparatus according to the embodiment may generate a TB ina manner that a border of the chunk is identical to a border of the TB.

Thereafter, the broadcast signal transmission apparatus segments atleast one TB such that it can generate at least one symbol. All symbolscontained in the object may be identical to each other. In addition, thelast symbol of TB may include a plurality of padding bytes such that allsymbols contained in the object have the same length.

The broadcast signal transmission apparatus may packetize at least onesymbol. For example, the broadcast signal transmission apparatus maygenerate the LCT packet on the basis of at least one symbol.

Thereafter, the broadcast signal transmission apparatus may transmit thegenerated LCT packet.

In accordance with the embodiment, the broadcast signal transmissionapparatus first generates the fragment payload, and generates thefragment header so as to generate the fragment. In this case, thebroadcast signal transmission apparatus may generate a TB correspondingto media data contained in the fragment payload. For example, at leastTB corresponding to media data contained in the media data box (mdat)may be sequentially generated on a chunk basis. Thereafter, thebroadcast signal transmission apparatus may generate the TBcorresponding to the fragment header.

The broadcast signal transmission apparatus may transmit the generatedTB according to the generation order so as to broadcast the mediacontent in real time. In contrast, the broadcast signal receptionapparatus according to the embodiment first parses the fragment header,and then parses the fragment header.

The broadcast signal transmission apparatus may transmit data accordingto the parsing order when media data is pre-encoded or TB ispre-generated.

FIG. 34 illustrates a data processing time using a ROUTE protocolaccording to an embodiment of the present invention.

FIG. 34(a) shows the data structure according to the embodiment. Themultimedia data may include at least one object. Each object may includeat least one fragment. For example, one object may include two fragments(Fragment1 and Fragment 2).

The broadcast signal transmission apparatus may segment the fragmentinto one or more TBs. The TB may be a source block, and the followingdescription will hereinafter be given on the basis of the source block.

For example, the broadcast signal transmission apparatus may segment thefragment 1 into three source blocks (Source Block 0, Source Block 1, andSource Block 2), and may segment the fragment 2 into three source blocks(Source Block 3, Source Block 4, Source Block 5).

The broadcast signal transmission apparatus may independently transmiteach segmented source block. The broadcast signal transmission apparatusmay start transmission of each source block generated when or just aftereach source block is generated.

For example, the broadcast signal transmission apparatus can transmitthe source block 0 (S₀) after the source block 0 (S₀) has been generatedfor a predetermined time (t_(e0)˜t_(e1)). The transmission start time(t_(d0)) of the source block 0 (S₀) may be identical to the generationcompletion time (t_(d0)) or may be located just after the generationcompletion time (t_(d0)). Likewise, the broadcast signal transmissionapparatus may generate the source blocks 1 to 5 (Source Block 1 (S₁) toSource Block 5 (S₅)), and may transmit the generated source blocks 1 to5.

Therefore, the broadcast signal transmission apparatus according to theembodiment may generate a transmission standby time (D_(t2)) between astart time of generating one source block and another start time oftransmitting the source block. The transmission standby time (D_(t2))generated by the broadcast signal transmission apparatus is relativelyshorter than the transmission standby time (D_(t1)) generated by theconventional broadcast signal transmission apparatus. Therefore, thebroadcast signal transmission apparatus according to the embodiment cangreatly reduce a transmission standby time as compared to theconventional broadcast signal transmission apparatus.

The broadcast signal reception apparatus according to the embodimentreceives each segmented source block, and combines the received sourceblocks, such that it can generate at least one fragment. For example,the broadcast signal reception apparatus may receive the source block 0(S₀), the source block 1 (S₁), and the source block 2 (S₂), and combinethe received three source blocks (S₀, S₁, S₂) so as to generate thefragment 1. In addition, the broadcast signal reception apparatusreceives the source block 3 (S₃), the source block 4 (S₄), and thesource block 5 (S₅), and combines the received three source blocks (S₃,S₄, S₅) so as to generate the fragment 2.

The broadcast signal reception apparatus may separately generate eachfragment. The broadcast signal reception apparatus may reproduce eachfragment when or just after each fragment is generated. Alternatively,the broadcast signal reception apparatus may reproduce each fragmentwhen or just after the source block corresponding to each fragment istransmitted.

For example, the broadcast signal reception apparatus may generate thefragment 1 after receiving the source blocks 0 to 2 (S₀˜S₂) during apredetermined time (t_(d0)˜t_(d3)). For example, after the broadcastsignal reception apparatus receives the source blocks 0 to 2 (S₀˜S₂)during a predetermined time (t_(d0)˜t_(d3)), it can generate thefragment 1. Thereafter, the broadcast signal reception apparatus mayreproduce the generated fragment 1. The reproduction start time (t_(p0))of the fragment 1 may be identical to the generation time of thefragment 1 or may be located after the generation time of thefragment 1. In addition, a reproduction start time (t_(p0)) of thefragment 1 may be identical to a reception completion time of the sourceblock 2 (S₂) or may be located just after the reception completion timeof the source block 2 (S₂).

In the same manner, after the broadcast signal reception apparatusaccording to the embodiment receives the source blocks 3 to 5 (S₃˜S₅)during a predetermined time (t_(d3)˜t_(d6)), it may generate thefragment 2. Thereafter, the broadcast signal reception apparatus mayreproduce the fragment 2.

However, the scope or spirit of the present invention is not limitedthereto, and the broadcast signal reception apparatus according to theembodiment may receive the source block and may reproduce data in unitsof a received source block as necessary.

Therefore, the broadcast signal reception apparatus according to theembodiment may generate a reproduction standby time (D_(r2)) between areception start time of one fragment and a reproduction start time ofthe fragment. The reproduction standby time (D_(r2)) generated by thebroadcast signal reception apparatus is relatively shorter than thereproduction standby time (D_(r2)) generated by the broadcast signalreception apparatus. Therefore, the broadcast signal reception apparatusaccording to the embodiment can reduce a reproduction standby time ascompared to the conventional broadcast signal reception apparatus.

As described above, a predetermined time corresponding to the sum of atransmission standby time and a reproduction standby time may beconsiderably reduced. Here, the predetermined time may be needed whenone TB is transmitted from the broadcast signal transmission apparatusand is then reproduced by the broadcast signal reception apparatus. Thismeans that an initial access time during which the broadcast signalreception apparatus initially approaches the corresponding object isconsiderably reduced.

In case of using the ROUTE protocol, the broadcast signal transmissionapparatus may transmit data in units of a TB, and the broadcast signalreception apparatus may reproduce the received data in units of a TB ora fragment. As a result, a total time from an acquisition time ofmultimedia content to a content display time for a user can be reduced,and an initial access time required when the user approaches thebroadcast channel can also be reduced.

Therefore, TB transmission based on the ROUTE protocol is appropriatefor the real-time broadcast environment.

<Method for Identifying File Segmentation Generation and ConsumptionInformation>

FIG. 35 illustrates a Layered Coding Transport (LCT) packet structurefor file transmission according to an embodiment of the presentinvention.

An application layer transport session may be composed of an IP addressand a port number. If the application layer transport session is theROUTE protocol, the ROUTE session may be composed of one or more LCT(Layered Coding Transport) sessions. For example, if one media componentis transmitted through one LCT transport session, at least one mediacomponent may be multiplexed and transmitted through one applicationlayer transport session. In addition, at least one transport object maybe transmitted through one LCT transport session.

Referring to FIG. 35, if the application layer transmission protocol isbased on the LCT, each field of the LCT packet may indicate thefollowing information.

LCT version number field(V) indicates the protocol version number. Forexample, this field indicates the LCT version number. The version numberfield of the LCT header MUST be interpreted as the ROUTE version numberfield. This version of ROUTE implicitly makes use of version ‘1’ of theLCT building block. For example, the version number is ‘0001b’.

Congestion control flag field(C) indicates the length of CongestionControl Information field. C=0 indicates the Congestion ControlInformation (CCI) field is 32-bits in length. C=1 indicates the CCIfield is 64-bits in length. C=2 indicates the CCI field is 96-bits inlength. C=3 indicates the CCI field is 128-bits in length.

Reserved field(R) reserved for future use. For example, Reservedfield(R) may be Protocol-Specific Indication field (PSI).Protocol-Specific Indication field (PSI) may be used as an indicator fora specific purpose in the LCT higher protocol. PSI field indicateswhether the current packet is a source packet or an FEC repair packet.As the ROUTE source protocol only delivers source packets, this fieldshall be set to ‘10b’.

Transport Session Identifier flag field(S) indicates the length ofTransport Session Identifier field.

Transport Object Identifier flag field(O) indicates the length ofTransport Object Identifier field. For example, the object may indicateone file, and the TOI may indicate ID information of each object, and afile having TOI=0 may be referred to as FDT.

Half-word flag field (H) may indicate whether half-word (16 bits) willbe added to the length of TSI or TOI field.

Sender Current Time present flag field(T) indicates whether the SenderCurrent Time (SCT) field is present or not. T=0 indicates that theSender Current Time (SCT) field is not present. T=1 indicates that theSCT field is present. The SCT is inserted by senders to indicate toreceivers how long the session has been in progress.

Expected Residual Time present flag field(R) indicates whether theExpected Residual Time (ERT) field is present or not. R=0 indicates thatthe Expected Residual Time (ERT) field is not present. R=1 indicatesthat the ERT field is present. The ERT is inserted by senders toindicate to receivers how much longer the session/object transmissionwill continue.

Close Session flag field (A) may indicate whether session completion oran impending state of the session completion.

Close Object flag field (B) may indicate completion or impendingcompletion of a transmitting object.

LCT header length field(HDR_LEN): indicates total length of the LCTheader in units of 32-bit words.

Codepoint field(CP) indicates the type of the payload that is carried bythis packet.

Depending on the type of the payload, additional payload header may beadded to prefix the payload data.

Congestion Control Information field (CCI) may be used to transmitcongestion control information (e.g., layer numbers, logical channelnumbers, sequence numbers, etc.). The Congestion Control Informationfield in the LCT header contains the required Congestion ControlInformation.

Transport Session Identifier field (TSI) is a unique ID of a session.The TSI uniquely identifies a session among all sessions from aparticular sender. This field identifies the Transport Session in ROUTE.The context of the Transport Session is provided by the LSID (LCTSession Instance description).

LSID defines what is carried in each constituent LCT transport sessionof the ROUTE session. Each transport session is uniquely identified by aTransport Session Identifier (TSI) in the LCT header. LSID may betransmitted through the same ROUTE session including LCT transportsessions, and may also be transmitted through Web. The scope or spiritof a transmission unit of LSID is not limited thereto. For example, LSIDmay be transmitted through a specific LCT transport session havingTSI=0. LSID may include signaling information regarding all transportsessions applied to the ROUTE session. LSID may include LSID versioninformation and LSID validity information. In addition, LSID may includea transport session through which the LCT transport session informationis transmitted. The transport session information may include TSIinformation for identifying the transport session, source flowinformation that is transmitted to the corresponding TSI and providesinformation regarding a source flow needed for source data transmission,repair flow information that is transmitted to the corresponding TSI andprovides information regarding a repair flow needed for transmission ofrepair data, and transport session property information includingadditional characteristic information of the corresponding transportsession.

Transport Object Identifier field (TOI) is a unique ID of the object.The TOI indicates which object within the session this packet pertainsto. This field indicates to which object within this session the payloadof the current packet belongs to. The mapping of the TOI field to theobject is provided by the Extended FDT.

Extended FDT specifies the details of the file delivery data. This isthe extended FDT instance. The extended FDT together with the LCT packetheader may be used to generate the FDT-equivalent descriptions for thedelivery object. The Extended FDT may either be embedded or may beprovided as a reference. If provided as a reference the Extended FDT maybe updated independently of the LSID. If referenced, it shall bedelivered as in-band object on TOI=0 of the included source flow.

Header Extensions field may be used as an LCT header extension part fortransmission of additional information. The Header Extensions are usedin LCT to accommodate optional header fields that are not always used orhave variable size.

For example, EXT_TIME extension is used to carry several types of timinginformation. It includes general purpose timing information, namely theSender Current Time (SCT), Expected Residual Time (ERT), and Sender LastChange (SLC) time extensions described in the present document. It canalso be used for timing information with narrower applicability (e.g.,defined for a single protocol instantiation); in this case, it will bedescribed in a separate document.

FEC Payload ID field may include ID information of Transmission Block orEncoding Symbol. FEC Payload ID may indicate an ID to be used when theabove file is FEC-encoded. For example, if the FLUTE protocol file isFEC-encoded, FEC Payload ID may be allocated for a broadcast station orbroadcast server configured to identify the FEC-encoded FLUTE protocolfile.

Encoding Symbol(s) field may include Transmission Block or Encodingsymbol data.

The packet payload contains bytes generated from an object. If more thanone object is carried in the session, then the Transmission Object ID(TOI) within the LCT header MUST be used to identify from which objectthe packet payload data is generated.

The LCT packet according to the embodiment may include Real Time SupportExtension field (EXT_RTS) corresponding to an extension format of aHeader Extensions field. EXT_RTS may include segmentation generation andconsumption information of the file, and will hereinafter be referred toas fragment information. The LCT packet according to the embodimentincludes EXT_RTS corresponding to an extension format of the HeaderExtensions field, and may support real-time file transmission andconsumption information using a method compatible with the legacy LCT.

The fragment information (EXT_RTS) according to the embodiment mayinclude Header Extension Type field (HET), Fragment Start Indicatorfield (SI), Fragment Header flag field (FH), and Fragment HeaderComplete Indicator field (FC).

Header Extension Type field (HET) may indicate the corresponding HeaderExtension type. The HET field may be an integer of 8 bits. Basically, ifHET for use in LCT is in the range of 0 to 127, a variable-length headerextension in units of a 32-bit word is present, and the length of HET iswritten in the Header Extension Length field (HEL) subsequent to HET. IfHET is in the range of 128 to 255, Header Extension may have a fixedlength of 32 bits.

The fragment information (EXT_RTS) according to the embodiment has afixed length of 32 bits, such that the corresponding Header Extensiontype may be identified using one unique value from among the values of128 to 255, and may identify the corresponding Header Extension type.

SI field may indicate that the corresponding lCT packet includes a startpart of the fragment. If a user in the broadcast environment approachesa random access of a file through which the corresponding file-basedmultimedia content is transmitted, packets having” SI field=0″ fromamong the initial reception packets are discarded, the packets startingfrom a packet having “SI field=1” starts parsing, so that the packetprocessing efficiency and the initial delay time can be reduced.

FH field may indicate that the corresponding LCT packet includes thefragment header part. As described above, the fragment header ischaracterized in that a generation order and a consumption order of thefragment header are different from those of the fragment payload. Thebroadcast signal reception apparatus according to the embodiment mayrearrange transmission blocks sequentially received on the basis of theFH field according to the consumption order, so that it can regeneratethe fragment.

FC field may indicate that the corresponding packet includes the lastdata of the fragment. For example, if the fragment header is transmittedafter the fragment payload is first transmitted, the FC field mayindicate inclusion of the last data of the fragment header. If thefragment header is first transmitted and the fragment payload is thentransmitted, the FC field may indicate inclusion of the last data of thefragment payload. The following description will hereinafter disclose anexemplary case in which the fragment payload is first transmitted andthe fragment is then transmitted.

If the broadcast signal reception apparatus receives the packet having“FC field=1”, the broadcast signal reception apparatus may recognizereception completion of the fragment header, and may perform fragmentrecovery by combining the fragment header and the fragment payload.

Padding Bytes field (PB) may indicate the number of padding bytescontained in the corresponding LCT packet. In the legacy LCT, all LCTpackets corresponding to one object must be identical to each other.However, when a transmission block (TB) is divided according to the dataconstruction method, the last symbol of each TB may have a differentlength. Therefore, the broadcast signal transmission apparatus accordingto the embodiment fills a residual part of the packet with paddingbytes, such that it can support the real-time file transmission using afixed-length packet according to the method compatible with the legacyLCT.

Reserved field reserved for future use.

FIG. 36 illustrates a structure of an LCT packet according to anotherembodiment of the present invention.

Some parts of FIG. 36 are substantially identical to those of FIG. 35,and as such a detailed description thereof will herein be omitted, suchthat FIG. 36 will hereinafter be described centering on a differencebetween FIG. 35 and FIG. 36.

Referring to FIG. 36, fragment information (EXT_RTS) according toanother embodiment may include a Fragment Header Length field (FHL)instead of the FC field shown in FIG. 35.

FHL field indicates the number of constituent symbols of the fragment,so that it can provide specific information as to whether reception ofthe fragment is completed. The FHL field may indicate a total number ofsymbols corresponding to respective fragments including the fragmentheader and the fragment payload. In addition, the FHL field may indicatea total number of symbols to be transmitted later from among thefragment header and the fragment payload.

For example, if the fragment payload is first transmitted and thefragment header is then transmitted, the FHL field may indicate a totalnumber of symbols corresponding to the fragment header. In this case,the FHL field may indicate the length of the fragment header.

If the fragment header is first transmitted and the fragment payload isthen transmitted, the FHL field may indicate a total number of symbolscorresponding to the fragment payload. In this case, the FHL field mayindicate the length of the fragment payload.

The following description will hereinafter disclose an exemplary case inwhich the fragment payload is first transmitted and the fragment headeris then transmitted.

The broadcast signal reception apparatus according to another embodimentmay receive the LCT packet including the fragment header correspondingto the number of symbols displayed on the FHL field. The broadcastsignal reception apparatus checks the number of reception times of theLCT packet including the fragment header, so that it can identifyreception completion of the fragment header. Alternatively, thebroadcast signal reception apparatus checks the number of TBscorresponding to the fragment header, so that it can identify receptioncompletion of the fragment header.

<Method for Identifying Segmentation Generation and SegmentationConsumption Information of File>

FIG. 37 illustrates real-time broadcast support information signalingbased on FDT according to an embodiment of the present invention.

Referring to FIG. 37, the present invention relates to a method foridentifying segmentation generation and segmentation consumptioninformation of file-based multimedia content in a real-time broadcastenvironment. The segmentation generation and segmentation consumptioninformation of the file-based multimedia content may include theabove-mentioned data structure and LCT packet information.

The broadcast signal transmission apparatus may further transmitadditional signalling information so as to identify segmentationgeneration information and segmentation consumption information of thefile. For example, the signalling information may include metadata adout-of-band signaling information.

A method for transmitting signaling information regarding the real-timebroadcast support information according to the embodiment is shown inFIG. 37.

The broadcast signal transmission apparatus according to the embodimentmay transmit signaling information either through a File Delivery Table(FDT) level or through a file-level Real-Time-Support attribute. IfReal-Time-Support is set to 1, objects written in the corresponding FDTlevel or File level may include the above-mentioned data structure andpacket information, such that file segmentation generation andconsumption in the real-time broadcast environment can be indicated.

FIG. 38 is a block diagram illustrating a broadcast signal transmissionapparatus according to an embodiment of the present invention.

Referring to FIG. 38, the broadcast signal transmission apparatus fortransmitting broadcast signals including multimedia content using thebroadcast network may include a signaling encoder 21005, a TransmissionBlock Generator 21030, and/or a Transmitter 21050.

The signaling encoder 21005 may generate signaling information. Thesignaling information may indicate whether multimedia content will betransmitted in real time. The signaling information may indicate thatthe above-mentioned multimedia content is transmitted from among atleast one of the file level and the FDT level in real time.

If the signaling information indicates real-time transmission of themultimedia content, the Transmission Block Generator 21030 may dividethe file contained in the multimedia content into one or more TB scorresponding to data that is independently encoded and transmitted.

The transmitter 21050 may transmit the transmission block (TB).

A detailed description thereof will hereinafter be described withreference to FIG. 39.

FIG. 39 is a block diagram illustrating a broadcast signal transmissionapparatus according to an embodiment of the present invention.

Referring to FIG. 39, the broadcast signal transmission apparatus fortransmitting broadcast signals including multimedia content using thebroadcast network according to the embodiment may include a signalingencoder (not shown), a Media Encoder 21010, a Fragment Generator 21020,a Transmission Block Generator 21030, a Packetizer 21040, and/or aTransmitter 21050.

The signaling encoder (not shown) may generate signaling information.The signaling information may indicate whether multimedia content willbe transmitted in real time.

Media Encoder 21010 may encode multimedia content so that it cangenerate media data using the encoded multimedia content. Hereinafter,the term “media data” will be referred to as data.

Fragment Generator 21020 may segment each file constructing themultimedia content, so that it can generate at least one fragmentindicating a data unit that is independently encoded and reproduced.

Fragment Generator 21020 may generate the fragment payload constructingeach fragment and then generate the fragment header.

Fragment Generator 21020 may buffer media data corresponding to thefragment payload. Thereafter, the Fragment Generator 21020 may generatea chunk corresponding to the fragment payload on the basis of thebuffered media data. For example, the chunk may be a variable-sized dataunit composed of the same media data as in GOP of video data.

If generation of the chunk corresponding to the fragment payload is notcompleted, the Fragment Generator 21020 continuously buffers the mediadata, and completes generation of the chunk corresponding to thefragment payload.

Fragment Generator 21020 may determine whether data corresponding to thefragment payload is generated as a chunk whenever the chunk isgenerated.

If the chunk corresponding to the fragment payload is completedgenerated, Fragment Generator 21020 may generate the fragment headercorresponding to the fragment payload.

Transmission Block Generator 21030 may generate at least one TBindicating a data unit that is encoded and transmitted through fragmentsegmentation.

The transmission block (TB) according to the embodiment may indicate aminimum data unit that is independently encoded and transmitted withoutdepending on the preceding data. For example, the TB may include one ormore chunks composed of the same media data as in GOP of video data.

Transmission Block Generator 21030 may first transmit the TBcorresponding to the fragment payload, and may generate the TBcorresponding to the fragment header.

Transmission Block Generator 21030 may generate as a single TB. However,the scope or spirit of the present invention is not limited thereto, andthe Transmission Block Generator 21030 may generate the fragment headeras one or more TB s.

For example, if Fragment Generator 21020 generates the fragment payloadconstructing each fragment and then generates the fragment header, theTransmission Block Generator 21030 generates the transmission block (TB)corresponding to the fragment payload and then generates the TBcorresponding to the fragment header.

However, the scope or spirit of the present invention is not limitedthereto. If the fragment header and the fragment payload for themultimedia content are generated, the TB corresponding to the fragmentheader may be first generated and the TB corresponding to the fragmentpayload may be generated.

Transmission Block Generator 21030 may generate a transmission block(TB) corresponding to the fragment payload and a TB corresponding to thefragment header as different TB s.

Packetizer 21040 may divide the TB into one or more equal-sized symbols,so that the one or more symbols may be packetized into at least onepacket. However, the scope or spirit of the present invention is notlimited thereto, and the symbols may also be generated by other devices.In accordance with the embodiment, the symbols may have the same length.However, the last symbol of each TB may be less in length than othersymbols.

Thereafter, Packetizer 21040 may packetize at least one symbol into oneor more packets. For example, the packet may be an LCT packet. Thepacket may include a packet header and a packet payload.

The packet header may include fragment information having specificinformation regarding file segmentation generation and segmentationconsumption. The file segmentation generation may indicate that data isdivided into at least one chunk or at least one TB capable ofindependently encoding/transmitting the file constructing the multimediacontent. The file segmentation consumption may indicate that at leastone fragment capable of performing independent decoding/reproducing bycombination of at least one TB is recovered and is reproduced on afragment basis. In addition, segmentation consumption of the file mayinclude data that is reproduced on a TB basis.

For example, the fragment information may include at least one of an SIfield indicating that a packet includes initial data of the fragment, anFH field indicating that a packet includes header data, fragmentcompletion information indicating that generation of a TB correspondingto each fragment is completed, and a PB field indicating the number ofpadding bytes contained in a packet.

The fragment information may further include a Header Extension Type(HET) field indicating the type of a Header Extension of thecorresponding packet.

The fragment completion information may include at least one of the FCfield indicating that a packet includes the last data of the fragmentheader and the FHL field indicating a total number of symbolscorresponding to the fragment header.

The fragment information may be generated by Packetizer 21040, and maybe generated by a separate device. The following description willhereinafter described on the basis of an exemplary case in which thepacketizer 21040 generates the fragment information.

Packetizer 21040 may identify whether the generated symbol includesfirst data of the fragment.

For example, the packetizer 21040 may identify whether the generatedsymbol has first data of the fragment payload. If the generated symbolhas first data of the fragment payload, the SI field may be set to 1. Ifthe generated symbol does not have first data of the fragment payload,the SI field may be set to zero ‘0’.

Packetizer 21040 may identify whether the generated symbol has data ofthe fragment payload or data of the fragment header.

For example, if the generated symbol has data of the fragment payload,the FH field may be set to 1. If the generated symbol does not have dataof the fragment payload, the FH field may be set to zero ‘0’.

Packetizer 21040 may identify whether generation of a TB correspondingto each fragment is completed. If fragment completion informationindicating generation completion of a TB corresponding to each fragmentmay include the FC field indicating inclusion of the last data of thefragment header.

For example, if the generated symbol has data of the fragment header andis the last symbol of the corresponding TB, the FC field may be setto 1. If the generated symbol does not have data of the fragment headeris not identical to the last symbol of the corresponding TB, the FCfield may be set to zero ‘0’.

Packetizer 21040 may identify whether the generated symbol is the lastsymbol of the corresponding TB and has a length different from that ofanother symbol. For example, another symbol may be a symbol having apredetermined length, and the symbol having a different length fromother symbols may be shorter in length than other symbols.

For example, if the generated symbol is the last symbol of thecorresponding TB and has a different length from other symbols, thepacketizer 21040 may insert the padding bytes into a packetcorresponding to the last symbol of each TB. The packetizer 21040 maycalculate the number of padding bytes.

In addition, the PB field may indicate the number of padding bytes. Thepadding byte is added to each symbol having a shorter length than othersymbols in such a manner that all symbols may have the same length.Alternatively, the padding bytes may be the remaining parts other thansymbols of the packet.

If the generated symbol is not identical to the last symbol of thecorresponding TB or has a different length from other symbols, the PBfield may be set to zero ‘0’.

The packet payload may include at least one symbol. The followingdescription will hereinafter disclose an exemplary case in which onepacket includes one symbol.

The packet having the last symbol of each TB may include at least onepadding byte.

Transmitter 21050 may transmit one or more packet in the order of TBgeneration.

For example, the transmitter 21050 may first transmit the TBcorresponding to the fragment payload, and then transmit the TBcorresponding to the fragment header.

However, the scope or spirit of the present invention is not limitedthereto. If the fragment header and the fragment payload arepre-generated for multimedia content, the transmitter 21050 according tothe embodiment may first transmit the TB corresponding to the fragmentheader, and then transmit the TB corresponding to the fragment payload.

FIG. 40 is a flowchart illustrating a process for generating andtransmitting in real time the file-based multimedia content according toan embodiment of the present invention.

FIG. 40 is a flowchart illustrating a method for transmitting broadcastsignals using the above-mentioned broadcast signal transmissionapparatus shown in FIG. 39.

Referring to FIG. 40, the broadcast signal transmission apparatusaccording to the embodiment may encode multimedia content using theMedia Encoder 21010 in step S11100. The broadcast signal transmissionapparatus may encode multimedia content and then generate media data.

Thereafter, the broadcast signal transmission apparatus may performbuffering of media data corresponding to the fragment payload in stepS11200. The broadcast signal transmission apparatus may generate a chunkcorresponding to the fragment payload on the basis of the buffered mediadata.

If generation of the chunk corresponding to the fragment payload is notcompleted, the broadcast signal transmission apparatus continuouslyperform buffering of media data, and then completes generation of thechunk corresponding to the fragment payload in step S11300.

Thereafter, the broadcast signal transmission apparatus may divide eachfile constructing the multimedia content using the fragment generator21020, such that it may generate at least one fragment indicating a dataunit that is independently decoded and reproduced in step S11400.

The broadcast signal transmission apparatus may generate the fragmentpayload constructing each fragment, and then generate the fragmentheader.

The broadcast signal transmission apparatus may determine whether alldata corresponding to the fragment payload is generated as a chunkwhenever the chunk is generated.

If generation of the chunk corresponding to the fragment payload iscompleted, the broadcast signal transmission apparatus may generate thefragment header corresponding to the fragment payload.

The broadcast signal transmission apparatus divides the fragment usingthe transmission block generator 21030, so that it can generate at leastone TB indicating a data unit that is independently encoded andtransmitted in step S11500.

For example, when the fragment header is generated after the fragmentpayload constructing each fragment has been generated, the broadcastsignal transmission apparatus may generate the TB corresponding to thefragment payload and then generate the TB corresponding to the fragmentheader.

The broadcast signal transmission apparatus may generate a TBcorresponding to the fragment payload and a TB corresponding to thefragment header as different TBs.

Thereafter, the broadcast signal transmission apparatus may divide theTB into one or more equal-sized symbols using the packetizer 21040, andmay packetize at least one symbol into at least one packet in stepsS11600 and S11700.

A method for generating a packet using the broadcast signal transmissionapparatus has already been disclosed in FIG. 40, and as such a detaileddescription thereof will herein be omitted for convenience ofdescription.

Thereafter, the broadcast signal transmission apparatus may control thetransmitter 21050 to transmit one or more packets in the order of TBgeneration.

FIG. 41 is a flowchart illustrating a process for allowing the broadcastsignal transmission apparatus to generate packets using a packetizeraccording to an embodiment of the present invention.

Referring to FIG. 41, the broadcast signal transmission apparatus mayidentify whether the generated symbol has first data of the fragment instep S11710.

For example, if the generated symbol has first data of the fragmentpayload, the SI field may be set to 1 in step S11712. If the generatedsymbol does not include first data of the fragment payload, the SI fieldmay be set to zero ‘0’ in step S11714.

Thereafter, the broadcast signal transmission apparatus may identifywhether the generated symbol has data of the fragment payload or data ofthe fragment header in step S11720.

For example, if the generated symbol has data of the fragment payload,the FH field may be set to 1 in step S11722. If the generated symboldoes not have data of the fragment payload, the FH field may be set tozero ‘0’ in step S11724.

The broadcast signal transmission apparatus may identify whethergeneration of the TB corresponding to each fragment is completed in stepS11730.

For example, if the generated symbol has data of the fragment header andis the last symbol of the corresponding TB, the FC field may be set to 1in step S11732. If the generated symbol does not have data of thefragment header or is not identical to the last symbol of thecorresponding TB, the FC field may be set to zero ‘0’ in step S11734.

Thereafter, the broadcast signal transmission apparatus may identifywhether the generated symbol is the last symbol of the corresponding TBand has a different length from other symbols in step S11740.

For example, if the generated symbol is the last symbol of thecorresponding TB and has a different length from other symbols, thebroadcast signal transmission apparatus may insert the padding bytesinto a packet corresponding to the last symbol of each TB. The broadcastsignal transmission apparatus may calculate the number of padding bytesin step S11742. The PB field may indicate the number of padding bytes.

If the generated symbol is not identical to the last symbol of thecorresponding TB or has a different length from other symbols, the PBfield may be set to zero ‘0’ in step S11744.

The packet payload may include at least one symbol.

FIG. 42 is a flowchart illustrating a process forgenerating/transmitting in real time the file-based multimedia contentaccording to another embodiment of the present invention.

Referring to FIG. 42, contents shown in FIGS. 40 and 41 from among allcontents of FIG. 42 are substantially identical to each other, and assuch a detailed description thereof will herein be omitted forconvenience of description.

In accordance with another embodiment, the broadcast signal transmissionapparatus may use the FHL field instead of the FC field. For example,the above-mentioned fragment information may include fragment completioninformation indicating generation completion of a TB corresponding toeach fragment. The fragment completion information may include the FHLfield indicating a total number of symbols corresponding to the fragmentheader.

The broadcast signal transmission apparatus according to the embodimentmay calculate the number of symbols corresponding to the TB includingdata of the fragment header, and may record the calculated result in theFHL field in step S12724.

The FHL field may indicate the length of a fragment header as a totalnumber of symbols corresponding to the fragment header. The FHL fieldmay be contained in the fragment information instead of theabove-mentioned FC field in such a manner that the broadcast signalreception apparatus can identify reception completion of the fragmentheader.

The broadcast signal reception apparatus according to the embodimentchecks the number of transmission times of a packet including as manyfragment headers as the number of data pieces recorded in the FHL field,so that it can identify whether or not the fragment header is received.

FIG. 43 is a block diagram illustrating a file-based multimedia contentreceiver according to an embodiment of the present invention.

Referring to FIG. 43, the broadcast signal reception apparatus fortransmitting a broadcast signal including multimedia content using thebroadcast network may include a receiver (not shown), a signalingdecoder 22005, a Transmission Block Regenerator 22030, and/or a MediaDecoder 22060.

The signaling decoder 22005 may decode signaling information. Thesignaling information may indicate whether the multimedia content willbe transmitted in real time.

If the signaling information indicates real-time transmission of themultimedia content, Transmission Block Regenerator 22030 combinesbroadcast signals, so that it can recover at least one TB indicating adata unit that is independently encoded and transmitted.

Media Decoder 22060 may decode the TB.

A detailed description thereof will hereinafter be described withreference to FIG. 44.

FIG. 44 is a block diagram illustrating a file-based multimedia contentreceiver according to an embodiment of the present invention.

Referring to FIG. 44, the broadcast signal reception apparatus accordingto the embodiment may include a receiver (not shown), a signalingdecoder (not shown), a Packet Filter 22010, a Packet Depacketizer 22020,a Transmission Block Regenerator 22030, a Fragment Regenerator 22040, aFragment Parser 22050, a Media Decoder 22060, and/or a Media Renderer22070.

The receiver (not shown) may receive a broadcast signal. The broadcastsignal may include at least one packet. Each packet may include a packetheader including fragment information and a packet payload including atleast one symbol.

The signaling decoder 22005 may decode signaling information. Thesignaling information may indicate whether the multimedia content willbe transmitted in real time.

Packet Filter 22010 may identify a fragment start time starting from atleast one packet received at an arbitrary time, and may start packetprocessing from the fragment start time.

Packet Filter 22010 may identify the fragment start time on the basis ofthe SI field of fragment information contained in the packet. If PacketFilter 22010 indicates that the corresponding packet includes a startpart of the fragment, the previous packets of the corresponding packetare discarded and some packets starting from the corresponding packetmay be transmitted to the packet depacketizer 22020.

For example, the packet filter 22010 discards the previous packets, eachof which is set to 1, and some packet starting from the correspondingpacket that is set to 1 may be filtered.

The packet depacketizer 22020 may depacketize at least one packet, andmay extract fragment information contained in the fragment header and atleast one symbol contained in the packet payload.

Transmission Block Regenerator 22030 may combine packets so that it canrecover at least one TB indicating a data unit that is independentlyencoded and transmitted. The recovered TB may include data correspondingto the fragment header, and may include data corresponding to thefragment payload.

Fragment Regenerator 22040 combines at least one TB, completes recoveryof the fragment header and the fragment payload, and combines thefragment header and the fragment payload, so that the fragmentregenerator 22040 may recover the fragment indicating a data unit thatis independently decoded and reproduced.

Fragment Regenerator 22040 combines the TB on the basis of fragmentinformation, so that the fragment regenerator 22040 may recover thefragment payload and the fragment header. Fragment Regenerator 22040 mayfirst recover the fragment payload in the order of reception packets,and may recover the fragment header.

If the FH field indicates that the packet has data of the fragmentheader, the fragment regenerator 22040 may combine at least one TBcorresponding to the fragment header so that it recovers the fragmentheader according to the combined result.

If the FH field indicates that the packet does not include data of thefragment header, the Fragment Regenerator 22040 may recover the fragmentpayload by combining at least one TB.

For example, if the FH field is set to zero ‘0’, the FragmentRegenerator 22040 may determine fragment payload so that it can recoverthe fragment payload. If the FH field is set to 1, the fragmentregenerator 22040 determines the fragment header so that it can recoverthe fragment header.

Thereafter, if Fragment Regenerator 22040 completes recovery of thefragment payload and the fragment header corresponding to each fragment,the recovered fragment payload and the recovered fragment header arecombined so that the fragment is recovered.

There are two methods for allowing the fragment regenerator 22040 todetermine whether recovery of the fragment payload and the fragmentheader corresponding to each fragment has been completed.

The first method is to use the FC field contained in the fragmentinformation.

The fragment completion information may include the FC field indicatingthat the packet has the last data of the fragment header. If the FCfield indicates that the packet has the last data of the fragmentheader, the Fragment Regenerator 22040 determines that the fragmentheader constructing each fragment and the fragment payload have beenreceived, and can recover the fragment header and the fragment payload.

For example, if the fragment payload constructing each fragment is firstreceived and the fragment header is then received, the FC field mayindicate that the corresponding packet includes the last data of thefragment header.

Therefore, if the FC field indicates that the corresponding packet hasthe last data of the fragment header, the Fragment Regenerator 22040 mayrecognize reception completion of the fragment header and may recoverthe fragment header. Thereafter, the Fragment Regenerator 22040 maycombine the fragment header and the fragment payload so as to recoverthe fragment.

If the FC field indicates that the corresponding packet has the lastdata of the fragment header, the broadcast signal reception apparatusmay repeat a process for recovering the transmission block (TB).

For example, if the FC field is not set to 1, the broadcast signalreception apparatus may repeat the recovery process of the TB. If the FCfield is set to 1, the Fragment Regenerator 22040 may recover thefragment by combination of the fragment header and the fragment payload.

The second method can determine whether recovery of the fragment payloadconstructing each fragment and the fragment header has been completed onthe basis of the FHL field contained in the fragment information.

The Fragment Regenerator 22040 may count the number of packets includingdata of the fragment header.

The fragment completion information may further include the FHL fieldindicating a total number of symbols corresponding to the fragmentheader. If the value recorded in the FHL field is identical to thenumber of packets having data of the fragment header, the FragmentRegenerator 22040 may recover the fragment header and the fragmentpayload.

A detailed description of a method for allowing the fragment regenerator22040 to use the FHL field is shown in FIG. 44.

Fragment Parser 22050 may parse the recovered fragment. Since thefragment header is located at the front of the recovered fragment andthe fragment payload is located at the rear of the recovered fragment,the Fragment Parser 22050 may first parse the fragment header and thenparse the fragment payload.

Fragment Parser 22050 may parse the recovered fragment so that it cangenerate at least one media access unit. For example, the media accessunit may include at least one media data. The media access unit may havea unit of media data having a predetermined size.

Media Decoder 22060 may decode the fragment. Media Decoder 22060 maydecode at least one media access unit so as to generate media data.

Media Renderer 22070 may render the decoded media data so as to performpresentation.

FIG. 45 is a flowchart illustrating a process for receiving/consuming afile-based multimedia content according to an embodiment of the presentinvention.

Contents shown in FIG. 44 can be equally applied to the broadcast sigalreception method according to the embodiment.

Referring to FIG. 45, a broadcast signal reception method for receivingmultimedia content including at least one file includes: receiving themultimedia content divided into at least one packet; recovering at leastone TB indicating a data unit that is independently encoded andtransmitted by packet combination; and completing recovery of thefragment header and the fragment payload by combination of one or moreTBs, recovering a fragment indicating a data unit that is independentlyencoded and reproduced by combination of the fragment header and thefragment payload, and/or performing fragment decoding.

The broadcast signal reception apparatus according to the embodiment mayreceive a broadcast signal using the receiver (not shown) in stepS21010. The broadcast signal may include at least one packet.

Thereafter, the broadcast signal reception apparatus according to theembodiment may control the packet filter 22010 to identify a fragmentstart time from at least one packet received at an arbitrary time instep S21020.

Thereafter, the broadcast signal reception apparatus according to theembodiment may depacketize at least one packet using the packetdepacketizer 22020, so that it can extract at least one symbol containedin the fragment information and packet payload contained in the packetheader in step S21030.

Thereafter, the broadcast signal reception apparatus combines packetsusing the transmission block regenerator 22030, so that it can recoverat least one TB indicating a data unit that is independently encoded andtransmitted in step S21040. The reproduced TB may include datacorresponding to the fragment header, and may include data correspondingto the fragment payload.

The broadcast signal reception apparatus according to the embodiment maycontrol the fragment regenerator 22040 to identify whether the TBreproduced on the basis of fragment information is a TB corresponding tothe fragment header and a TB corresponding to the fragment payload instep S21050.

Thereafter, the broadcast signal reception apparatus may combine therecovered TB so that it can recover the fragment payload and thefragment header.

If the FH field indicates that the packet does not include data of thefragment header, the broadcast signal reception apparatus combines atleast one TB corresponding to the fragment payload so that it canrecover the fragment payload in step S21060.

If the FH field indicates that the packet has data of the fragmentheader, the broadcast signal reception apparatus may recover thefragment header by combination of at least one TB corresponding to thefragment header in step S21070.

The broadcast signal reception apparatus may determine whether thefragment payload constructing each fragment and the fragment header onthe basis of the FC field contained in fragment information have beencompletely recovered in step S21080.

If the FC field indicates that the corresponding packet does not havethe last data of the fragment header, the broadcast signal receptionapparatus may repeat the TB recovery process.

If the FC field indicates that the corresponding packet has the lastdata of the fragment, the broadcast signal reception apparatus maydetermine reception completion of each fragment.

For example, if the fragment header is received after the fragmentpayload constructing each fragment is first received, the FC field mayindicate that the corresponding packet has the last data of the fragmentheader.

Therefore, if the FC field indicates that the packet has the last dataof the fragment header, the broadcast signal reception apparatusdetermines that the fragment header constructing each fragment and thefragment payload have been completely received, so that it can recoverthe fragment header and the fragment payload.

If the FC field indicates that the corresponding packet does not havethe last data of the fragment header, the broadcast signal receptionapparatus may repeat the TB recovery process.

Thereafter, the broadcast signal reception apparatus may combine atleast one TB using the Fragment Regenerator 22040 to complete recoveryof the fragment header and the fragment payload, and may combine thefragment header and the fragment payload to recover the fragmentindicating a data unit that is independently decoded and reproduced instep S21090.

The broadcast signal reception apparatus according to the embodiment mayparse the recovered fragment using the fragment parser 22050 in stepS21090. The broadcast signal reception apparatus parses the recoveredfragment so that it can generate at least one media access unit.However, the scope or spirit of the present invention is not limitedthereto, and the broadcast signal reception apparatus parses the TB sothat it can generate at least one media access unit.

Thereafter, the broadcast signal reception apparatus according to theembodiment may decode at least one media access unit using the mediadecoder 22060, so that it can generate media data in step S21100.

The broadcast signal reception apparatus according to the embodiment mayperform rendering of the decoded media data using the media renderer22070 so as to perform presentation in step S21110.

FIG. 46 is a flowchart illustrating a process for receiving/consuming inreal time a file-based multimedia content according to anotherembodiment of the present invention.

Referring to FIG. 46, some parts of FIG. 46 are substantially identicalto those of FIG. 45, and as such a detailed description thereof willherein be omitted.

The broadcast signal reception apparatus according to the embodiment maydetermine whether the fragment header and the fragment payloadconstructing each fragment have been completely received on the basis ofthe FHL field.

The broadcast signal reception apparatus according to the embodiment mayallow the fragment regenerator 22040 to identify whether the TBrecovered on the basis of fragment information is a TB corresponding tothe fragment header or a TB corresponding to the fragment payload instep S22050.

Thereafter, the broadcast signal reception apparatus combines therecovered TBs so that it can recover each of the fragment payload andthe fragment header.

If the FH field indicates that the corresponding packet has datacorresponding to the fragment payload, the broadcast signal receptionapparatus may combine at least one TB so that it can recover thefragment payload in step S22060.

If the FH field indicates that the corresponding packet has datacorresponding to the fragment header, the Fragment Regenerator 22040 mayrecover the fragment header by combination of at least one TB in stepS22070.

Thereafter, if the broadcast signal reception apparatus completesrecovery of the fragment payload constructing each fragment and thefragment header, the fragment signal reception apparatus may recover thefragment by combination of the recovered fragment payload and thefragment header.

The broadcast signal reception apparatus may determine whether thefragment payload constructing each fragment and the fragment header havebeen completely reproduced on the basis of the FHL field contained infragment information.

The broadcast signal reception apparatus may count the number (N) ofpackets constructing each fragment in step S22080. For example, thebroadcast signal reception apparatus may count the number of packetseach having data of the fragment header. One packet may include at leastone symbol, and the following description will hereinafter describe anexemplary case in which one packet includes one symbol.

The FHL field may indicate the number of symbols constructing thefragment. If as many packets as the number of symbols recorded in theFHL field are not received, the broadcast signal reception apparatus mayrepeat the TB recovery process. For example, if reception of thefragment payload constructing each fragment and the fragment header isnot completed, the broadcast signal reception apparatus may repeat theTB recovery process.

Fragment completion information may further include the FHL fieldindicating a total number of symbols corresponding to the fragmentheader.

If the value recorded in the FHL field is identical to the number ofpackets, the broadcast signal reception apparatus determines that thefragment payload constructing each fragment and the fragment header havebeen completely received, and then recovers the fragment header and thefragment payload in step S22090.

For example, the FHL field may indicate a total number of symbolscorresponding to each fragment including both the fragment header andthe fragment payload. In this case, if as many packets as the number ofsymbols recorded in the FHL field are received, the broadcast signalreception apparatus can determine that the fragment payload constructingeach fragment and the fragment header have been completely received.

For example, the FHL field may indicate a total number of symbols to betransmitted later from among the fragment header and the fragmentpayload.

If the fragment payload constructing each fragment is first received andthe fragment header is then received, the FHL field may indicate a totalnumber of symbols corresponding to the fragment header. In this case,the number of symbols recorded in the FHLfield is identical to thenumber of packets corresponding to the received fragment header, thebroadcast signal reception apparatus may determine that the fragmentpayload constructing each fragment and the fragment header have beencompletely received.

In addition, if the fragment header constructing each fragment is firstreceived and the fragment payload is then received, the FHL field mayindicate a total number of symbols corresponding to the fragmentpayload. In this case, if the number of symbols recorded in the FHLfield is identical to the number of packets corresponding to thereceived fragment payload, the broadcast signal reception apparatus maydetermine that the fragment payload constructing each fragment and thefragment header have been completely received.

Thereafter, if the fragment payload constructing each fragment and thefragment header have been completely received, the broadcast signalreception apparatus combines the fragment header and the fragmentpayload so as to recover the fragment in step S22100.

It will be appreciated by those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

Both apparatus and method inventions are mentioned in this specificationand descriptions of both of the apparatus and method inventions may becomplementarily applicable to each other.

MODE FOR THE INVENTION

Various embodiments have been described in the best mode for carryingout the invention.

INDUSTRIAL APPLICABILITY

The present invention is available in a series of broadcast signalprovision fields.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1-15. (canceled)
 16. An apparatus for transmitting a broadcast signal,comprising: a packetizer for generating at least one Layered CodingTransport (LCT) packet, wherein the at least one LCT packet is used totransport at least one delivery object and signaling data, wherein eachof the at least one delivery object is a part of a file, wherein the atleast one delivery object is carried in a transport session, and whereinthe signaling data includes real time information indicating whether ornot the transport session carries streaming media; and a transmitter fortransmitting the broadcast signal comprising the at least one LCTpacket.
 17. The apparatus according to claim 16, wherein the real timeinformation is included in at least one of a file level and a FileDelivery Table (FDT) level of the signaling data.
 18. The apparatusaccording to claim 16, wherein the delivery object is generated throughsegmentation of a fragment, wherein the fragment is generated throughsegmentation of the file.
 19. The apparatus according to claim 18,wherein a header of the LCT packet includes fragment information havinginformation regarding file segmentation generation and segmentationconsumption.
 20. The apparatus according to claim 19, wherein thefragment information includes a Fragment Start Indicator (SI) fieldindicating that the LCT packet has initial data of the fragment.
 21. Theapparatus according to claim 19, wherein the fragment informationincludes a Fragment Header flag (FH) field indicating that the LCTpacket has data of a fragment header.
 22. The apparatus according toclaim 19, wherein the fragment information includes at least one of afragment completion information indicating that generation of thedelivery object corresponding to the fragment is completed, and apadding bytes (PB) field indicating the number of padding bytescontained in the LCT packet.
 23. The apparatus according to claim 22,wherein the fragment completion information includes: a Fragment HeaderComplete Indicator (FC) field indicating that the LCT packet has lastdata of the fragment header; and a Fragment Header Length (FHL) fieldindicating a total number of symbols corresponding to the fragmentheader.
 24. A method for transmitting a broadcast signal, comprising:generating at least one Layered Coding Transport (LCT) packet, whereinthe at least one LCT packet is used to transport at least one deliveryobject and signaling data, wherein each of the at least one deliveryobject is a part of a file, wherein the at least one delivery object iscarried in a transport session, and wherein the signaling data includesreal time information indicating whether or not the transport sessioncarries streaming media; and transmitting the broadcast signalcomprising the at least one LCT packet.
 25. The method according toclaim 24, wherein the real time information is included in at least oneof a file level and a File Delivery Table (FDT) level of the signalingdata.
 26. The method according to claim 24, wherein the delivery objectis generated through segmentation of a fragment, wherein the fragment isgenerated through segmentation of the file.
 27. The method according toclaim 26, wherein a header of the LCT packet includes fragmentinformation having information regarding file segmentation generationand segmentation consumption.
 28. The method according to claim 27,wherein the fragment information includes a Fragment Start Indicator(SI) field indicating that the LCT packet has initial data of thefragment.
 29. The method according to claim 27, wherein the fragmentinformation includes at least one of a Fragment Header flag (FH) fieldindicating that the LCT packet has data of a fragment header, a fragmentcompletion information indicating that generation of the delivery objectcorresponding to the fragment is completed, and a padding bytes (PB)field indicating the number of padding bytes contained in the LCTpacket.
 30. The method according to claim 29, wherein the fragmentcompletion information includes: a Fragment Header Complete Indicator(FC) field indicating that the LCT packet has last data of the fragmentheader; and a Fragment Header Length (FHL) field indicating a totalnumber of symbols corresponding to the fragment header.